Core: Cleanup locale handling.

It also fixes the recent problem of strange strings.

--HG--
branch : trunk

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

@@ -1710,9 +1710,9 @@ void GameObject::EventInform(uint32 eventId)
 }
 
 // overwrite WorldObject function for proper name localization
-const char* GameObject::GetNameForLocaleIdx(int32 loc_idx) const
+const char* GameObject::GetNameForLocaleIdx(LocaleConstant loc_idx) const
 {
-    if (loc_idx >= 0)
+    if (loc_idx != DEFAULT_LOCALE)
     {
         uint8 uloc_idx = uint8(loc_idx);
         if (GameObjectLocale const *cl = sObjectMgr.GetGameObjectLocale(GetEntry()))