Eluna add new system for userdata management. single userdata with GC.

Note that this will still need the core side destructors to have the ref remove function used in order to have invalid pointer errors.

HookMgr.h

@@ -37,6 +37,8 @@ struct AreaTriggerEntry;
 class ReactorAI;
 typedef ReactorAI ScriptedAI;
 #else
+#undef UNORDERED_MAP
+#define UNORDERED_MAP   std::unordered_map
 struct ScriptedAI;
 #endif
 class AuctionHouseObject;
@@ -321,7 +323,8 @@ enum GossipEvents
 class HookMgr
 {
 public:
-    friend class ACE_Singleton<HookMgr, ACE_Thread_Mutex>;
+    int userdata_table;
+    void RemoveRef(const void* obj) const;
 
     CreatureAI* GetAI(Creature* creature);