Integrate Diproche as a lose/flexable dependency #4

Merlins prolog-code currently lives as a couple of prolog-code-files that we received via Email. For starters, we should put these in a separate folder of ours and read them into our prolog-VM (made usable in #3). We should try to get the prolog-code into it's own git repository though, install it via npm and then load it from there.