Core/Spells: Use SpellDifficulty.dbc to check casterAuraSpell, excludeCasterAuraSpell, targetAuraSpell and excludeTargetAuraSpell

Scripts/Icecrown Citadel: Fixed Mutated Abomination not being able to eat ooze on heroic mode
Scripts/Icecrown Citadel: Removed some obsolete code

Closes #523, #1447

src/server/game/Globals/ObjectMgr.cpp

@@ -8016,7 +8016,7 @@ bool ObjectMgr::CheckDeclinedNames(std::wstring w_ownname, DeclinedName const& n
 
         if (mainpart != GetMainPartOfName(wname, i+1))
             x = false;
- 
+
         if (w_ownname != wname)
             y = false;
     }