Add ReactiveCocoa-Mac static library target
Add ReactiveCocoa-Mac to script/cibuild
Add all headers to ReactiveCocoa-Mac

Also fix a couple that were erroneously in/not in ReactiveCocoa and ReactiveCocoa-iOS
Merge remote-tracking branch 'origin/master' into mac-static-library
Build EXTRuntimeExtensions into static library too
Merge pull request #819 from ReactiveCocoa/mac-static-library

OS X static library