Lots of things to make menus and submenus work.

Also added wxPopTransientWindow::CanDismiss() which will
    be needed for pop-up menus, although that actually
    still has to be done...


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@14436 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/popupwin.h

@@ -86,6 +86,10 @@ public:
 
     // hide the window
     virtual void Dismiss();
+    
+
+    virtual bool CanDismiss()
+        { return TRUE; }
 
     // called when a mouse is pressed while the popup is shown: return TRUE
     // from here to prevent its normal processing by the popup (which consists