[7336] Implemented new BattleGroundQueue invitation system. Now it supports premade group versus premade group matches.

Added 2 new config options - InvitationType and PremadeGroupWaitForMatch - you can find more info in default config file.
    This patch can cause crashes.

Author: Triply

[7338] Little cleanup in battleground queues code. Author: ApoC

--HG--
branch : trunk

src/game/Group.cpp

@@ -1348,7 +1348,7 @@ uint32 Group::CanJoinBattleGroundQueue(BattleGroundTypeId bgTypeId, BattleGround
     if(!reference)
         return BG_JOIN_ERR_OFFLINE_MEMBER;
 
-    uint32 queue_id = reference->GetBattleGroundQueueIdFromLevel(bgTypeId);
+    BGQueueIdBasedOnLevel queue_id = reference->GetBattleGroundQueueIdFromLevel(bgTypeId);
     uint32 arenaTeamId = reference->GetArenaTeamId(arenaSlot);
     uint32 team = reference->GetTeam();