Add support for making new product on-the-fly during mobile ordering

let's face it, that will be necessary sometimes.  this feature still needs some
work before can be called complete though...

tailbone/views/master.py

@@ -1045,6 +1045,7 @@ class MasterView(View):
         """
         defaults = {
             'request': self.request,
+            'mobile': True,
             'readonly': self.viewing,
             'model_class': getattr(self, 'model_row_class', None),
             'action_url': self.request.current_route_url(_query=None),