add Speed.limited
Put most general C40 opening first; fixes #13
Merge pull request #19 from tobiasvl/reorder-c40

Put most general C40 opening first; fixes #13
Adding antichess (kamikazee chess) variant
Moved responsibility of generating the list of moves to Variant. Changed a couple of minor things as per code review.
Moving stalemate responsibility out to variant. Since in suicide chess, the winner is not the previous player, the variant also determines the winner