Fixes #4203: On Firefox 2 the context menu may not close on mouse click
Fixes #4203: On Firefox 2 the context menu may not close on mouse click

Apparently this bug happened because:
1. clicking on the blank area of the screen
causes the menu widget to be deselected (IE, the focus manager call _onBlur())
but it doesn't actually remove focus from the MenuItem.
2. Then when dijit.focus(menuItem.focusNode) is called, the focus manager
was ignoring it, and not realizing that the Menu had been opened.
3. Since focus manager thinks that nothing is open it ignores the background click

Patched for now; may want a better solution later.

git-svn-id: 674a2d6b1e32e53f607eb824547723f32280967e@10228 560b804f-0ae3-0310-86f3-f6aa0a117693

redaktor/deliteful