[Bug-gnubg] Adding backgammon variants to gnubg

[George]

In Greece we play two variants along with backgammon. One is "plakoto" and the other is "fevga". I'm planning to develop software to play those two games and I was wondering if the gnubg codebase can be modified to play variants. From web searching it seems gnubg can't help me, but I wanted to make sure before I start developing from scratch.