Can't reliably get this information from cmake (#1267), so it's
misleading to show these messages at all. We can always revert this
commit if we find a way later.
- Leave src as include dir (for includes to recognize 'nvim/' prefix).
- Change subdirectory from src to src/nvim.
- Fix msgpack generation.
- Fix some other paths to new locations.
- Cleanup source tree, leaving only files necessary for compilation/testing
- Process files through unifdef to remove tons of FEAT_* macros
- Process files through uncrustify to normalize source code formatting.
- Port the build system to cmake
