Lobby code completed

I have added the lobby so that any number of players can now join. Basically when a player hits their start button (or enter if using a keyboard) they get taken to the lobby and an entry is made for them automatically. Other players then hit start on their own controllers. Future versions will allow for a character selection here, but for now there's nothing else to do except hit start once more when ready, and when all players have done this the game loads.