Add a build system to ease compilation and installation

[ddwek]

Hi Andrii, I was playing stall for a long time and I think that I can contribute with ideas for new features or improvements to the existing ones.
Actually, I already cloned the repo and I made some changes locally. The main enhancement is to support the GNU Build System (which is based on configure.ac and Makefile.am files on the top level directory) to generate suitable and portable Makefiles, so that you can easily provide a directory prefix where to install the game.
If you agree, I could fork the repo to my profile, push the changes on a new branch "contrib" and open a pull request for you to fetch that branch, review the propossed changes and merge them, if appropriate.

Best regards!

Daniel