Update grid system. Try to fix some crashes and transport passengers (now they are despawned after a while).

src/server/game/Entities/Creature/Creature.h

@@ -440,7 +440,7 @@ class Creature : public Unit, public GridObject<Creature>, public MapCreature
 {
     public:
 
-        explicit Creature();
+        explicit Creature(bool isWorldObject = false);
         virtual ~Creature();
 
         void AddToWorld();
@@ -707,6 +707,9 @@ class Creature : public Unit, public GridObject<Creature>, public MapCreature
         uint32 GetGUIDTransport() { return guid_transport; }
 
         void FarTeleportTo(Map* map, float X, float Y, float Z, float O);
+
+        bool m_isTempWorldObject; //true when possessed
+
     protected:
         bool CreateFromProto(uint32 guidlow, uint32 Entry, uint32 vehId, uint32 team, const CreatureData* data = NULL);
         bool InitEntry(uint32 entry, uint32 team=ALLIANCE, const CreatureData* data=NULL);