Core/Scripts: Split OnCreatureCreate() and OnGameObjectCreate() into two virtual functions each.

Note to scripters: be aware that you will need to hook into the Remove functions if you want to do stuff at GO/creature removal.
Closes issue 5011.

--HG--
branch : trunk

src/server/game/OutdoorPvP/OutdoorPvP.cpp

@@ -590,11 +590,11 @@ void OutdoorPvP::TeamApplyBuff(TeamId team, uint32 spellId, uint32 spellId2)
     TeamCastSpell(OTHER_TEAM(team), spellId2 ? -(int32)spellId2 : -(int32)spellId);
 }
 
-void OutdoorPvP::OnGameObjectCreate(GameObject *go, bool add)
+void OutdoorPvP::OnGameObjectCreate(GameObject *go)
 {
     if (go->GetGoType() != GAMEOBJECT_TYPE_CAPTURE_POINT)
         return;
 
     if (OPvPCapturePoint *cp = GetCapturePoint(go->GetDBTableGUIDLow()))
-        cp->m_capturePoint = add ? go : NULL;
+        cp->m_capturePoint = go;
 }

src/server/game/OutdoorPvP/OutdoorPvP.h

@@ -219,8 +219,8 @@ class OutdoorPvP : public ZoneScript
         // setup stuff
         virtual bool SetupOutdoorPvP() {return true;}
 
-        void OnGameObjectCreate(GameObject *go, bool add);
-        void OnCreatureCreate(Creature *, bool /*add*/) {}
+        void OnGameObjectCreate(GameObject *go);
+        void OnCreatureCreate(Creature *) {}
 
         // send world state update to all players present
         void SendUpdateWorldState(uint32 field, uint32 value);