Currently, model can have zones ; templates can have zones.
The templates that worth are the templates ones. The model only complete it.

Now, model zones must worth that means :

• graphical zones that are not in the model should not render (and should render a red debug error in the backoffice for dev purposes)
• model zones that are not rendered through graphical impl always apears at the bottom of the template (with a red debug error in the backoffice for dev purposes)