[8608] implement BattleGround Alterac Valley

sql won't be included - please look at your database
providers forum

also note, that creature_loot_template id 0
is used for the loot of dead players in this bg
(after a player died and you remove insignia from him..
he not only drops money - he drops some random items too)

further work must be done in better code for adjusting right
levels to creatures - maybe using something similar like it's
done in heroic instances

also quests and creatures needs some scripts in future

thanks to:
netsky - initial start of this patch
bogie - 2nd person writing on this patch
triply, kapatejib, vladimir - code review and suggestions
arrai - for his great tool and help
and all testers / code contributers - I won't write
down a list, else I would forget most probably one ^^

src/game/SpellEffects.cpp

@@ -3044,7 +3044,7 @@ void Spell::EffectOpenLock(uint32 effIndex)
             if (BattleGround *bg = player->GetBattleGround())
             {
                 // check if it's correct bg
-                if (bg && bg->GetTypeID() == BATTLEGROUND_AB)
+                if (bg->GetTypeID() == BATTLEGROUND_AB || bg->GetTypeID() == BATTLEGROUND_AV)
                     bg->EventPlayerClickedOnFlag(player, gameObjTarget);
                 return;
             }