Cleanup sniper implementation.
Add dead player lobbies. closes #45, closes #42

* Add zlobby command.
* Set default permssions on games to true.
* Add lobby location to ZombieGame.
* End games when the last living player leaves.
* Forcibly remove player signs when game ends.
* Forcibly spawn players when game ends.
* Spawn dead players in lobby locaiton if defined.