Core/Creature: Implement FarTeleportTo (teleport to an other map)

Core/Transport: Cleanup and optimize transport and passenger handling
- Only transports will be active objects
  - Reduced cpu and memory usage
- Using FarTeleportTo for creature passengers at transport teleportation
  - Creatures won't be recreated on teleport

--HG--
branch : trunk

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

@@ -674,6 +674,8 @@ class Creature : public Unit, public GridObject<Creature>
 
         void SetGUIDTransport(uint32 guid) { guid_transport=guid; }
         uint32 GetGUIDTransport() { return guid_transport; }
+
+        void FarTeleportTo(Map* map, float X, float Y, float Z, float O);
     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);