Core/Spells: Implement Battleground - Dampening for wintergrasp

sql/updates/world/2012_08_26_03_world_spell_area.sql

@@ -0,0 +1,3 @@
+DELETE FROM `spell_area` WHERE spell=74411 AND `area`=4197;
+INSERT INTO `spell_area` (`spell`,`area`,`quest_start`,`quest_start_active`,`quest_end`,`aura_spell`,`racemask`,`gender`,`autocast`) VALUES
+(74411,4197,0,0,0,0,0,2,1);

src/server/game/Spells/SpellMgr.cpp

@@ -1177,6 +1177,16 @@ bool SpellArea::IsFitToRequirements(Player const* player, uint32 newZone, uint32
                 return battlefieldWG->IsEnabled() && (player->GetTeamId() == battlefieldWG->GetDefenderTeam()) && !battlefieldWG->IsWarTime();
             break;
         }
+        case 74411: // Battleground - Dampening
+        {
+            if (!player)
+                return false;
+
+            if (Battlefield* bf = sBattlefieldMgr->GetBattlefieldToZoneId(player->GetZoneId()))
+                return bf->IsWarTime();
+            break;
+        }
+
     }
 
     return true;