Add @rpavlik's git revision cmake files to Stalefish

[sebjameswml]

So that the git revision can be compiled into the code and output into .h5 files

[sebjameswml]

See https://stackoverflow.com/questions/1435953/how-can-i-pass-git-sha1-to-compiler-as-definition-using-cmake
and
https://github.com/rpavlik/cmake-modules