fix windows test run
unit test round 2
attempting to fix ccache use on darwin
made ccache optional, no longer pulls clang on darwin build
fixing darwin build from Dockerfile
fixed missing nproc on OSX
updated readme to include regtest example, build examples
fix QT unit tests
made -j get passed down, added build.sh
This contains significant rebase / merge / testing work by Naut
<lbrynaut@protonmail.com>, Anthony Fieroni <bvbfan@abv.bg> and Brannon
King <countprimes@gmail.com>.
Add a patch that seems to be necessary for compatibilty of libevent
2.0.22 with recent mingw-w64 gcc versions (at least GCC 5.3.1 from Ubuntu
16.04).
Without this patch the Content-Length in the HTTP header ends up as
`Content-Length: zu`, causing communication between the RPC
client and server to break down. See discussion in #8653.
Source: https://sourceforge.net/p/levent/bugs/363/
Thanks to @sstone for the suggestion.
