Have 4v4 added in since UGC is has a 4v4 now.

UGC's 4v4 season is starting this week on friday, and I think it would be nice to have 4v4 on TF2center, since I know teams are signed up and ready for it. I think it should use the same/similar cfgs and whitelist as UGC has it, and the idea of no heavy and medic out together being allowed.