This allows for v2 container NewGRFs to be created. Hashes are needed for building the baseset metadata, so the .hash files are stored the source tree so they can be built if grfcodec and grfid are not present.
The hash of openttd.grf is not actually needed, but it is simpler to leave it in than handle only orig_extra.grf.
CMake works on all our supported platforms, like MSVC, Mingw, GCC,
Clang, and many more. It allows for a single way of doing things,
so no longer we need shell scripts and vbs scripts to work on all
our supported platforms.
Additionally, CMake allows to generate project files for like MSVC,
KDevelop, etc.
This heavily reduces the lines of code we need to support multiple
platforms from a project perspective.
Addtiionally, this heavily improves our detection of libraries, etc.
