licences: Fix Wolf3D and Doom licences

The EULA's under which the code was released isn't the same, unless I'm
mistaken. I don't think this applies to Quake 1: quakespasm, to my
knowledge, does not require code that isn't GPL'ed.
zandronum-1.2: Don't hardcode PV
licences: Introduce Quake2-EULA
Introduce games-fps/yquake2