[6828] Added script name indexing for creature, gameobject, item, areatrigger and instance scripts.

* loaded all distinct script names into one vector at server startup
* added custom loaders to convert the script names to indices
* converted all the script lookup functions to use the index instead of the name

src/game/GameObject.h

@@ -355,7 +355,7 @@ struct GameObjectInfo
             uint32 data[24];
         } raw;
     };
-    char   *ScriptName;
+    uint32 ScriptId;
 };
 
 struct GameObjectLocale