Mafia: Team Talk command, lynch.killVoters

-lynch.killVoters will kill players who voted for the lynched player based on the voting order (first 2, last 3, etc).
-Team Talk can be given to a few roles to allow them to communicate with each other in the chat (useful for big mafia sides)
Merge pull request #471 from IceKirby/patch-41

Mafia: Team Talk command, lynch.killVoters