Error 0 was previously: "URL not well formed"
But actually , this wasn't the exact reason why an error 0 can be returned.
Error 0 means that no server are reachable to even respond.
So I have replaced it by "Server not found".
Excluding EntityShapeVisualizer from Children list
Now a name is given to the EntityShape of the EntityShapeVisualizer (used to display the zone)
so we can now exclude them from the children list when it's time to figure if there are children for an entity.
(This is a better approach than excluding al the local entities)
The name has been used because it gives better results than trying to use the id map that arrive always too late.
The name is unique for a session, it includes a UUID.
