fad95e8da6 doc: Split build linux dependencies (MarcoFalke)
0000009015 doc: Split depends installation instructions per arch (MarcoFalke)
Pull request description:
The current depends installation instructions fail on bionic with
```
E: Unable to locate package g++-4.8-aarch64-linux-gnu
E: Unable to locate package gcc-4.8-aarch64-linux-gnu
E: Unable to locate package g++-4.8-arm-linux-gnueabihf
E: Unable to locate package gcc-4.8-arm-linux-gnueabihf
```
Also, they fail due to missing dependencies `make automake cmake pkg-config python3`
Fix this by removing the explicit version and splitting them into common instructions and instructions per linux architecture.
Tree-SHA512: 25d5efa7450a0b1bbd569f431158f5a25bf4fe34f6adc32ebdfd6b6db9447ce083f555f20ff5b9f7c458864986c15d65219a31a1cd2b18bad9965ece2ea5e3be
not that temporary anymore
Tree-SHA512: c44bfca71573b3d70001d339138715fc6fbceae2e370f2e1e8ba5bdfdb19e8ec4b0a59d45ff8565e0f784d4659f51e8089a6d892a73362b428d8a98097fc8532
a2a04a5abb Bugfix: Only run bitcoin-tx tests when bitcoin-tx is enabled (Luke Dashjr)
92af71cea9 configure: Make it possible to build only one of bitcoin-cli or bitcoin-tx (Luke Dashjr)
Pull request description:
Includes #5618 (which the reasons for rejecting no longer hold true)
Tree-SHA512: f30a8e4a2f70166b7cabef77c4674163b3a9da14c6a547d34f00d1056a19bf4d23e22851eea726fad2afc8735d5473ae91122c770b65ac3886663dc20e2c5b70
7ac911afe7 [docs] Add release notes for removing `-usehd` (John Newbery)
25548b2958 [wallet] Remove -usehd (John Newbery)
Pull request description:
`-usehd` is no longer used (except to tell the user that they've set it incorrectly for the wallet that they're loading). Remove it (in the same spirit as #14272)
Tree-SHA512: 5bdcd2bb9bb8504a01343595bcd1bd433d97b730255152c725103c1ac3fa3a9d9e5220a4c29d4c72307cf803e1c09d31080f83603c23dc77263846e17b1826f0
b6718e373e tests: Use MakeUnique to construct objects owned by unique_ptrs (practicalswift)
Pull request description:
A subset of #14211 ("Use MakeUnique to construct objects owned by unique_ptrs") as suggested by @MarcoFalke in https://github.com/bitcoin/bitcoin/pull/14211#issuecomment-423324019.
Use `MakeUnique` to construct objects owned by `unique_ptr`s.
Rationale:
* `MakeUnique` ensures exception safety in complex expressions.
* `MakeUnique` gives a more concise statement of the construction.
Tree-SHA512: 1228ae6ce7beb178d79142c4e936b728178ccaa8aa35c6d8feeb33d1a667abfdd010c59996a9d833594611e913877ce5794e75953d11d9b1fdbac04aa491d9cf
a2eb6f5405 [rpc] Add getnodeaddresses RPC command (chris-belcher)
Pull request description:
Implements issue https://github.com/bitcoin/bitcoin/issues/9463
New getnodeaddresses call gives access via RPC to the peers known by the node. It may be useful for bitcoin wallets to broadcast their transactions over tor for improved privacy without using the centralized DNS seeds. getnodeaddresses is very similar to the getaddr p2p method.
Please advise me on the best approach for writing an automated test. By my reading the getaddr p2p method also isn't really tested.
Tree-SHA512: ad03abf518847476495b76a2f5394b8030aa86654429167fa618e21460abb505c10ef9817ec1b80472320d41d0aff5dc94a8efce023aaaaf5e81386aa92b852b
New getnodeaddresses call gives access via RPC to the peers known by
the node. It may be useful for bitcoin wallets to broadcast their
transactions over tor for improved privacy without using the
centralized DNS seeds. getnodeaddresses is very similar to the getaddr
p2p method.
Tests the new rpc call by feeding IP address to a test node via the p2p
protocol, then obtaining someone of those addresses with
getnodeaddresses and checking that they are a subset.
f1bd03eb01 [depends, zmq, doc] upgrade zeromq to 4.2.5 and avoid deprecated zeromq api functions (mruddy)
Pull request description:
Upgrade the ZeroMQ dependency from version 4.2.3 to the latest stable version 4.2.5.
This PR Follows the lead of https://github.com/bitcoin/bitcoin/pull/11986.
I upgraded both patch files to correspond to the version `4.2.5` libzmq files.
I assume doing so is still necessary and correct.
Without updating the patch line numbers, things appear to work, but you get extra log messages while building `depends` because things don't exactly match, e.g.:
```
/bitcoin/depends> make zeromq
Extracting zeromq...
/bitcoin/depends/sources/zeromq-4.2.5.tar.gz: OK
Preprocessing zeromq...
patching file src/windows.hpp
Hunk #1 succeeded at 58 (offset 3 lines).
patching file src/thread.cpp
Hunk #1 succeeded at 307 with fuzz 2 (offset 87 lines).
Hunk #2 succeeded at 323 with fuzz 2 (offset 90 lines).
```
Updating the patches seemed cleaner, so I did it. Note that libzmq had some whitespace changes, so that's why the updated patches do too.
More info: https://github.com/zeromq/libzmq/releases/tag/v4.2.5
tags: libzmq, zmq, 0mq
Tree-SHA512: 78659dd276b5311e40634b1bbebb802ddd6b69662ba3c84995ef1e3795c49a78b1635112c7fd72a405ea36e2cc3bdeb84e6d00d4e491a349bba1dafff50e2fa5
faea5bfc5a doc: release notes for -enablebip61 default change (MarcoFalke)
fa14b54a87 p2p: Disable BIP 61 by default (MarcoFalke)
Pull request description:
The live p2p network should not be used for debugging or as development aid when implementing the p2p protocol. Instead, applications should be tested locally (e.g. by inspecting the debug log of a validating node on the local network)
Using the p2p network for this purpose seems wasteful and even dangerous, as peers can not be trusted to send the correct reject messages or a reject message at all.
Tree-SHA512: 9c91ad035b5110942172a3b4b8a332a84e0c0aa9ee80f8134aeab63e66ac604841e68b04038681c288b716e5e0cbe38065eb5c7eb63fa72c3bdb3255a4b2d99d
e351a16a2a Remove reference to deprecated RPC call in build instructions (Michael Goldstein)
a6f16f1b1a Docs: Add disable-wallet section to OSX build instructions (Michael Goldstein)
Pull request description:
The `disable-wallet` section was mentioned in the `Berkeley DB` section of the OSX build instructions, but the section did not actually exist. This PR ports the section from the Unix build instructions.
Tree-SHA512: e32f10f3b92307325f2101e89d3e18c89346916e70117c208ad7441170c4aee65b636ea4f7dd1cb0ecf0e800c1aa7c37fa73125e69ecdd539bc862e651b79b16
This commit does the following changes:
- [wallet] Remove 'account' argument from GetLegacyBalance()
- GetLegacyBalance() is never called with an account argument.
Remove the argument and helper functions.
- [wallet] Remove CWallet::ListAccountCreditDebit()
- Function no longer used.
- [wallet] Remove AccountMove()
- Function no longer used.
- [wallet] Remove AddAccountingEntry()
- Function no longer used.
- [wallet] Remove GetAccountCreditDebit()
- Function no longer used.
- [wallet] Don't rewrite accounting entries when reordering wallet transactions.
- Accounting entries are deprecated. Don't rewrite them to the wallet
database when re-ordering transactions.
- [wallet] Remove WriteAccountingEntry()
- Function no longer used.
- [wallet] Don't read acentry key-values from wallet on load.
- [wallet] Remove ListAccountCreditDebit()
- Function no longer used.
- [wallet] Remove CAccountingEntry class
- No longer used
- [wallet] Remove GetLabelDestination
- Function no longer used.
- [wallet] Delete unused account functions
- ReadAccount
- WriteAccount
- EraseAccount
- DeleteLabel
- [wallet] Remove fromAccount argument from CommitTransaction()
- [wallet] Remove strFromAccount.
- No longer used.
- [wallet] Remove strSentAccount from GetAmounts().
- No longer used.
- [wallet] Update zapwallettxes comment to remove accounts.
- [wallet] Remove CAccount
- No longer used
- [docs] fix typo in release notes for PR 14023
19efc01aec Add PSBT documentation (Pieter Wuille)
Pull request description:
This is just some initial text to get going; other contributions welcome.
I'd like to include other workflows, such as hardware wallets and (manual) coinjoins. However, the former will in practice require PSBT interfaces for existing hardware devices, and the second can really use some extra RPCs first.
Tree-SHA512: 951e475e31bb2ea9ab5d84d139b8bc436153ad035185f00ad1d56afc0c6f7c4de8176a785a6d0c38bb3fd9cbf318e513e1a032e83e1da99ded5d43a36f9cbc60
Now that 0.17 branch has been split off, master is 0.17.99 (pre-0.18).
Also clean out release notes.
Tree-SHA512: bb20025d3ead3346afc7a6a51af715783e705e1de9d1b90ced6423d8969d64e42b72d06a1eb853083b11e9cfe674775266792ae2cd18ed6c858938e125edab03
3fc20632a3 qt: Set BLOCK_CHAIN_SIZE = 220 (DrahtBot)
2b6a2f4a28 Regenerate manpages (DrahtBot)
eb7daf4d60 Update copyright headers to 2018 (DrahtBot)
Pull request description:
Some trivial maintenance to avoid having to do it again after the 0.17 branch off.
(The scripts to do this are in `./contrib/`)
Tree-SHA512: 16b2af45e0351b1c691c5311d48025dc6828079e98c2aa2e600dc5910ee8aa01858ca6c356538150dc46fe14c8819ed8ec8e4ec9a0f682b9950dd41bc50518fa
a9e898a4ad docs: Link to python style guidelines from developer notes (Mason Simon)
Pull request description:
Initially I moved the python style guidelines from the functional test README, but some of the python rules are test-specific, and most of the developer notes doc is C++ centric, so just dropping a link seemed better.
Tree-SHA512: 9d4d5cc45526319a118595d90fcfad2c9aced22007aa096d8af04ba1b963312822804f4c15b0b227d66af49565034437691b7760e7ff6d1e3f8b10b898906362
95464c7519 doc: Improve command to generate list of authors for release notes (Mitchell Cash)
1c22cc1af1 doc: Update broken links to now point to gitian-build.py (Mitchell Cash)
Pull request description:
- Update broken links
- Improve command to generate list of authors for a release
---
I also note that it asks to ping **wumpus** on IRC, to assist in generating a list of merged pulls and sort them into categories based on labels. I tried to turn this into a simple one-liner as well (something like ``git log --merges --format="- \`%h\` %s (%an)" v0.16.0..v0.16.1``), but it didn't seem to capture everything I needed.
Would it be worthwhile **wumpus** open-sourcing his code into `contrib/devtools` so there is no single point of failure (even if it can manually be worked around).
Tree-SHA512: 8e7f0880ff07ce8fe67b74de3f2c4b78dafe2c95eefb0617fa319ff196232967cb22ee75a183a39f93bfc6e0bf85547689160139312cee5956af2c069b8a3b6a
f447a0a707 Remove program options from build system (Chun Kuan Lee)
11588c639e Replace boost program_options (Chun Kuan Lee)
Pull request description:
Concept from #12744, but without parsing negated options.
Tree-SHA512: 7f418744bb8934e313d77a5f162633746ef5d043de802b9c9cd9f7c1842e7e566eb5f171cd9e2cc13317281b2449c6fbd553fa4f09b837e6af2f5d2b2aabdca2
- Remove dependency on sed (sed was overkill when you can just add plain
text to the git log --format command)
- Sort resulting list of authors alphabetically (case-insensitive)
- Provide an example of how to only generate authors between versions
801cb307b5 doc: Add release notes for -printtoconsole and -debuglogfile changes (Samuel B. Atwood)
Pull request description:
This adds release notes relevant to the changes in #13004 and documented in command line help in #13614.
Tree-SHA512: ff320415afa9be1ace37ebf0a69ee5a7e6d4167465bc41111be062a556da9b8accfc39553fac610e68521c7ab2095126ace4f012a32f5e9f37cbec39cfa74b04
161e8d40a4 RPC: Add new getzmqnotifications method. (Daniel Kraft)
caac39b0ac Make ZMQ notification interface instance global. (Daniel Kraft)
Pull request description:
This adds a new RPC method `getzmqnotifications`, which returns information about all active ZMQ notification endpoints. This is useful for software that layers on top of bitcoind, so it can verify that ZeroMQ is enabled and also figure out where it should listen.
See #13526.
Tree-SHA512: edce722925741c84ddbf7b3a879fc9db1907e5269d0d97138fe724035d93ee541c2118c24fa92f4197403f380d0e25c2fda5ca6c62d526792ea749cf527a99a0
This adds a new RPC method "getzmqnotifications", which returns
information about all active ZMQ notification endpoints. This is useful
for software that layers on top of bitcoind, so it can verify that
ZeroMQ is enabled and also figure out where it should listen.
See https://github.com/bitcoin/bitcoin/issues/13526.
af6ac3b677 doc: Remove mention of Qt4 from build docs (Wladimir J. van der Laan)
462c71f71b test: Update travis to not test Qt4 anymore (Wladimir J. van der Laan)
907f73bbc5 gui: Remove QT_VERSION fallbacks for Qt < 5 (Wladimir J. van der Laan)
bad068ad9f build: Build system changes to support only Qt5 (Wladimir J. van der Laan)
Pull request description:
Implements #8263.
Qt4.x has been EOL since 2015, and at least Gentoo has, or is going to drop support for it. I wouldn't be surprised if other Linux distributions follow.
This removes Qt4 detection from the build system, as well as removes all Qt4 fallbacks from the code. Turns out there's more than I expected: this is going to make maintenance of the GUI code, as well as adding new features significantly easier.
(I know there's still some references left to qt4 in RPM and Debian build script, but I don't have the knowledge how to fix them)
Tree-SHA512: d495924fd4dda6f6566ba44ee96be7cbe62e69ba1ca993b80a8449f78da852b7f1bd3e8200d57cfa1d72233c340eeff4596fb0032ecbddc715d99aea63817d3f
c9924a2756 Fix incorrect shell quoting in FreeBSD build instructions. (murrayn)
Pull request description:
The current instructions suggest:
BDB_PREFIX='$PWD/db4'
which results in BDB_PREFIX being set, literally, to '$PWD/db4'.
Tree-SHA512: 4a920d7a506ff94fb12793f0b8161fdfe0798382cfa88290a0eadd6926843b577328f7159a55039e2655def7ddf2e7a1eaa3dd30490292d4a920c98759becf56
e56771365b Do not use uppercase characters in source code filenames (practicalswift)
419a1983ca docs: Add a note about the source code filename naming convention (practicalswift)
Pull request description:
Add a note about the source code filename naming convention.
Tree-SHA512: 8d329bd9e19bcd26e74b0862fb0bc2369b46095dbd3e69d34859908632763abd7c3d00ccc44ee059772ad4bae4460c2bcc1c0e22fd9d8876d57e5fcd346cea4b
16e3cd380a Clarify include recommendation (practicalswift)
6d10f43738 Enforce the use of bracket syntax includes ("#include <foo.h>") (practicalswift)
906bee8e5f Use bracket syntax includes ("#include <foo.h>") (practicalswift)
Pull request description:
When analysing includes in the project it is often assumed that the preferred bracket include syntax (`#include <foo.h>`) mentioned in `developer-docs.md` is used consistently. @sipa:s excellent circular dependencies script [`circular-dependencies.py`](50c69b7801/contrib/devtools/circular-dependencies.py) (#13228) is an example of a script making this reasonable assumption.
This PR enables automatic Travis checking of the include syntax making sure that the bracket syntax includes (`#include <foo.h>`) is used consistently.
Tree-SHA512: a414921aabe8e487ebed42f3f1cbd02fecd1add385065c1f2244cd602c31889e61fea5a801507ec501ef9bd309b05d3c999f915cec1c2b44f085bb0d2835c182
67e0e04140 [wallet] [docs] Update release notes for removing `getlabeladdress` (John Newbery)
81608178cf [wallet] [rpc] Remove getlabeladdress RPC (John Newbery)
Pull request description:
labels are associated with addresses (rather than addresses being
associated with labels, as was the case with accounts). The
getlabeladdress does not make sense in this model, so remove it.
getaccountaddress is still supported for one release as the accounts
API is deprecated.
Tree-SHA512: 7f45d0456248ebcc4e54dd34e2578a09a8ea8e4fceda75238ccea9d731dc99a3f3c0519b18a9739de17d2e6e59c9c2259ba67c9ae2e3cb2a40ddb14b9193fe29
cbede7dbfd [qt] OptionsDialog: add prune setting (Sjors Provoost)
Pull request description:
The default suggested value is 2 GB. Minimum is 1 GB (550 MB rounded up).
When the user toggles this setting, a strong warning appears that undoing requires re-downloading the chain:
<img width="478" alt="schermafbeelding 2018-05-15 om 12 35 24" src="https://user-images.githubusercontent.com/10217/40051858-7939cc20-583c-11e8-9120-327a75376732.png">
Tooltip points out that actual disk usage can be higher. It's a bit vague on the "advanced features", because I'm assuming anyone who needs to use `-rescan` and `-txindex` will read the documentation, and a more detailed text would needlessly confuse everyone else.
<img width="450" alt="schermafbeelding 2018-05-15 om 12 33 51" src="https://user-images.githubusercontent.com/10217/40051791-49d6156a-583c-11e8-97b9-7de6dfd8c481.png">
The UI uses gigabytes for readability and easy of use. There is also no manual pruning UI (`prune=1`). The user will have to use `bitcoin.conf` for those things.
Fixes#6461. When combined with #13029 the user, after pruning their node, can safely reset settings and/or use bitcoind without having to edit `bitcoin.conf`. However I don't think that's an essential prerequisite.
Tree-SHA512: e17aff276d7235fbd40796adb6431d430620788a753ee13bc064abd35d2edc4280a3d3cddc18e42b4e00edff13ed18fd4f2a966c6f0b43b689afd13673e0c4bf
2b30ccc30a [docs] update transifex doc link (Cristian Mircea Messel)
Pull request description:
The old link is no longer working.
#13364
Tree-SHA512: 5729b9eabbdf8e05cb60be1bedc7e21a2052bb2921dca8322d8348c3ea0f7ee33f2e2e32a19f21bbe2b93b48ed221cfcb020592d0e6b118b77ca34e14bb30b89
docs: Linked to the 'Building on FreeBSD' section of the Unix guide where it lists BSD specific guides.
Created a FreeBSD build guide (doc/build-freebsd.md).
Added in warning about the version of 'gdb' installed by default.
Removed the FreeBSD build instructions now that they have their own guide (doc/build-freebsd.md).
Updated the sentence to refer to the BSD guides in the 'doc' directory for more specific BSD build instructions.
Minor grammatical fix.
fa3c910bfe test: Move linters to test/lint, add readme (MarcoFalke)
Pull request description:
This moves the checks and linters from `devtools` to a subfolder in `test`. (Motivated by my opinion that the dev tools are mostly for generating code and updating the repo whereas the linters are read-only checks.)
Also, adds a readme to clarify that checks and linters are only meant to prevent bugs and user facing issues, not merely stylistic preference or inconsistencies. (This is motivated by the diversity in developers and work flows as well as existing code styles. It would be too disruptive to change all existing code to a single style or too burdensome to force all developers to adhere to a single style. Also note that our style guide is changing, so locking in at the wrong style "too early" would only waste resources.)
Tree-SHA512: 9b10e89f2aeaf0c8a9ae248aa891d74e0abf0569f8e5dfd266446efa8bfaf19f0ea0980abf0b0b22f0d8416ee90d7435d21a9f9285b66df43f370b7979173406
87fe292d89 doc: Mention disabling BIP61 in bips.md (Wladimir J. van der Laan)
fe16dd8226 net: Add option `-enablebip61` to configure sending of BIP61 notifications (Wladimir J. van der Laan)
Pull request description:
This commit adds a boolean option `-peersendreject`, defaulting to `1`, that can be used to disable the sending of [BIP61](https://github.com/bitcoin/bips/blob/master/bip-0061.mediawiki) `reject` messages. This functionality has been requested for various reasons:
- security (DoS): reject messages can reveal internal state that can be used to target certain resources such as the mempool more easily.
- bandwidth: a typical node sends lots of reject messages; this counts against upstream bandwidth. Also the reject messages tend to be larger than the message that was rejected.
On the other hand, reject messages can be useful while developing client software (I found them indispensable while creating bitcoin-submittx), as well as for our own test cases, so whatever the default becomes on the long run, IMO the functionality should be retained as option. But that's a discussion for later, for now it's simply a node operator decision.
Also adds a RPC test that checks the functionality.
Tree-SHA512: 9488cc53e13cd8e5c6f8eb472a44309572673405c1d1438c3488f627fae622c95e2198bde5ed7d29e56b948e2918bf1920239e9f865889f4c37c097c37a4d7a9
9d4f9421a4 doc: Bump to Ubuntu Bionic 18.04 in build-windows.md (Chun Kuan Lee)
Pull request description:
Windows starts to provide Ubuntu 18.04 WSL, it can be downloaded from Microsoft Store.
Tree-SHA512: a96ed03f36894ad867fd88631c1497eac7fc1cdaee8f59f36f34781df0b0f0b352a1bd8f09eba61002534fb7e0fe460006f223e37d61ad888197a36d17b43178
25b7ab9 doc: Add release notes for -includeconf (Karl-Johan Alm)
0f0badd test: Test includeconf parameter. (Karl-Johan Alm)
629ff8c -includeconf=<path> support in config handler, for including external configuration files (Karl-Johan Alm)
Pull request description:
Fixes: #10071.
Done:
- adds `-includeconf=<path>`, where `<path>` is relative to `datadir` or to the path of the file being read, if in a file
- protects against circular includes
- updates help docs
~~~Thoughts:~~~
- ~~~I am not sure how to test this in a neat manner. Feedback on this would be nice. Will dig/think though.~~~
Tree-SHA512: cb31f1b2f69fbc0890d264948eb2e501ac05cf12f5e06a5942f9c1539eb15ea8dc3cae817f4073aecb2fcc21d0386747f14f89d990772003a76e2a6d25642553
1e46d8a Get rid of ambiguous OutputType::NONE value (Russell Yanofsky)
Pull request description:
Based on suggestion by @sipa https://github.com/bitcoin/bitcoin/pull/12119#issuecomment-357982763
After #12119, the NONE output type was overloaded to refer to either an output type that couldn't be parsed, or to an automatic change output mode. This change drops the NONE enum and uses a simple bool to indicate parse failure, and a new CHANGE_AUTO enum to refer the change output type.
This change is almost a pure refactoring except it makes RPCs reject empty string ("") address types instead of treating them like they were unset. This simplifies the parsing code a little bit and could prevent RPC usage mistakes. It's noted in the release notes.
Follows up #12408 by @MarcoFalke
Followups for future PRs:
- [ ] Add explicit support for specifying "auto" in `ParseOutputType` as suggested by promag and sipa: https://github.com/bitcoin/bitcoin/pull/12729#issuecomment-374799567 and https://github.com/bitcoin/bitcoin/pull/12729#discussion_r175969481
- [ ] Add wallet `AddressChangeType` method to complement `TransactionChangeType`: https://github.com/bitcoin/bitcoin/pull/12729#discussion_r175969618.
Tree-SHA512: 8b08b272bcb177a0a9e556dcd965840a7fe601ef83ca97938b879c9b1a33b5b3f96939e1bceef11ba7c644ac21bfd6c1dbc6ca715cd1da4ace50475240e4ee48
39d2911 [Docs] Add version footnote to tor.md (Damian Williamson)
Pull request description:
[Docs] Add version footnote to tor.md
Added note to section 2, part -edits to `/etc/tor/torrc`- indicating this is only required for Tor version 0.2.7.0 and older, since section 3 states it is valid for Tor version 0.2.7.1 and newer. Added ref link from section 2 version footnote to section 3. Re-styled headings to work on GitHub -alternate heading style markup creation issue with numbered headings and thus headings and automatic heading links are broken-
Ref: [Issue# 12376](https://github.com/bitcoin/bitcoin/issues/12376)
Signed-off-by: Damian Williamson \<willtech@live.com.au\>
Tree-SHA512: 439f4ccc3e196011af448b220adf26b0e653ac589bf4cfbbc276c1500c9d08f209c9d6101e4d232857779d9f25164cfb222ed30e3d63de116f9121e6ebde31c3
Added note to section 2, part -edits to `/etc/tor/torrc`- indicating this is only required for Tor version 0.2.7.0 and older, since section 3 states it is valid for Tor version 0.2.7.1 and newer. Added ref link from section 2 version footnote to section 3. Re-styled headings to work on GitHub -alternate heading style markup creation issue with numbered headings and thus headings and automatic heading links are broken- Ref: [Issue# 12376](https://github.com/bitcoin/bitcoin/issues/12376)
Signed-off-by: Damian Williamson <willtech@live.com.au>
