Add CMake support for RHash

[uilianries]

Hi!

This PR brings two CMake files which can build the library and executable.

I see you are running semaphore to build this project, but I can't update it locally, so you can update your script with:

mkdir cmake && pushd cmake
cmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=../results
cmake --build . --target install
popd
/usr/bin/find results/ -exec ls -ld '{}' ';'

Regards!

[wdlkmpx]

I have issues cross compiling static stuff, this might help

This should be merged, if we believe in true justice ...