Ignore newly added non-overlay windows

This prevents e.g. the popup menu from statusmenu from appearing
as a toplevel window.

svn path=/trunk/; revision=185

js/ui/workspaces.js

@@ -600,6 +600,9 @@ Workspace.prototype = {
             return;
         }
         
+        if (!this._isOverlayWindow(win))
+            return;        
+
         let clone = this._addWindowClone(win);
 
         if (win._overlayHint) {