broadcast resizestop to nested grids "all the way down"

Author: Derek Moore

src/gridstack.js

@@ -678,10 +678,12 @@
 
             self.grid.end_update();
 
-            var nested_grid = o.find('.grid-stack');
-            if (nested_grid.length && event.type == 'resizestop') {
-                nested_grid.data('gridstack').on_resize_handler();
-                nested_grid.find('.grid-stack-item').trigger('resizestop');
+            var nested_grids = o.find('.grid-stack');
+            if (nested_grids.length && event.type == 'resizestop') {
+                nested_grids.each(function(index, el) {
+                    $(el).data('gridstack').on_resize_handler();
+                });
+                o.find('.grid-stack-item').trigger('resizestop');
             }
         };