Although CMAKE_FLAGS was already a Makefile variable, it didn't have an
empty default value meaning that extending the flags to CMake in a clean
way was difficult. Add a CMAKE_EXTRA_FLAGS variable which is appended to
the default flags.
This simply calls the install target in the build directory. IMHO I
think it's looking a bit hacky having a separate Makefile target to do
this rather than using the usual CMake workflow but mine is not to
reason why... [Also, I've copied ``cd build && make ...`` although I'm
sure ``$MAKE -C build/ ...`` is probably the Right Thing (TM).]
Note that you'll have to set CMAKE_INSTALL_PREFIX on the cmake command
line to change where this installs to.
- 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
