Core/Players: Don't set instanceId to 0 when player is on transport during loading, there CAN be transports inside instances

Core/Scripts: Added waypoint id to OnRelocate transport hook
Core/Scripts: Make use of ZoneScript::GetGameObjectEntry at gameobject creation (makes it possible to override gameobject entries in instances)
Core/Transports: Call InstanceScript::EventInform for transport events
Core/Transports: Use guid from db for transports, not just its entry - adds partial support for instancing them (still cannot use transports table for it, but can spawn manually now)
Scripts/Icecrown Citadel: Fixed crash in Deathbringer Saurfang when event is started by more than one person (can't do this anymore)

Closes isssue #3749.

--HG--
branch : trunk

src/server/game/Entities/GameObject/GameObject.cpp

@@ -153,6 +153,14 @@ bool GameObject::Create(uint32 guidlow, uint32 name_id, Map *map, uint32 phaseMa
 
     SetPhaseMask(phaseMask,false);
 
+    SetZoneScript();
+    if (m_zoneScript)
+    {
+        name_id = m_zoneScript->GetGameObjectEntry(guidlow, name_id);
+        if (!name_id)
+            return false;
+    }
+
     GameObjectInfo const* goinfo = sObjectMgr.GetGameObjectInfo(name_id);
     if (!goinfo)
     {
@@ -211,8 +219,6 @@ bool GameObject::Create(uint32 guidlow, uint32 name_id, Map *map, uint32 phaseMa
             break;
     }
 
-    SetZoneScript();
-
     LastUsedScriptID = GetGOInfo()->ScriptId;
 
     return true;