Because of the '$' in `if(DEFINED $ENV{VALGRIND_CHECK})` EXITFREE wasn't being
defined, so the `free_all_mem` wasn't being included or called in the resulting
binary.
This commit fixes that, and also adds includes needed for `free_all_mem`
compilation.
- 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