Core/Quests: Fixed remaining issues with quest crediting (note: previous commits did not introduce issues, only revealed them)

Core/DBLayer: Fixed more compile warnings
Core/Spells: Corrected code style from revision 634af79146

Closes issue #3956.

--HG--
branch : trunk

src/server/scripts/Spells/spell_quest.cpp

@@ -361,7 +361,7 @@ public:
                 if(Creature* pTarget = GetHitCreature())
                 {
                     pPlayer->CastSpell(pPlayer, SPELL_TRIGGER_AID_OF_THE_EARTHEN, true, NULL);
-                    pPlayer->KilledMonsterCredit(NPC_FALLEN_EARTHEN_DEFENDER, pTarget->GetGUID());
+                    pPlayer->KilledMonsterCredit(NPC_FALLEN_EARTHEN_DEFENDER, 0);
                     pTarget->ForcedDespawn();
                 }
             }