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/Spells/SpellMgr.cpp

@@ -4053,11 +4053,6 @@ void SpellMgr::LoadSpellCustomAttr()
             spellInfo->EffectImplicitTargetA[0] = TARGET_DEST_DEST;
             ++count;
             break;
-            // this is here until targetAuraSpell and alike support SpellDifficulty.dbc
-        case 70459: // Ooze Eruption Search Effect (Professor Putricide)
-            spellInfo->targetAuraSpell = 0;
-            ++count;
-            break;
         // THIS IS HERE BECAUSE COOLDOWN ON CREATURE PROCS IS NOT IMPLEMENTED
         case 71604: // Mutated Strength (Professor Putricide)
         case 72673: // Mutated Strength (Professor Putricide)