This commit removes the error returns from the BlockHeader.BlockSha,
MsgBlock.BlockSha, and MsgTx.TxSha functions since they can never fail and
end up causing a lot of unneeded error checking throughout the code base.
It also updates all call sites for the change.
This commit contains the entire btcnet repository along with several
changes needed to move all of the files into the chaincfg directory in
order to prepare it for merging. This does NOT update btcd or any of the
other packages to use the new location as that will be done separately.
- All import paths in the old btcnet test files have been changed to the
new location
- All references to btcnet as the package name have been changed to
chaincfg
- The coveralls badge has been removed since it unfortunately doesn't
support coverage of sub-packages
This is ongoing work toward #214.
