Added wxFrameBase::OnMenuOpen, and wxUSE_IDLEMENUUPDATES in platform.h

Experimental wxUpdateUIEvent::SetUpdateInterval() function to limit
UI update frequency


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@21746 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/x11/app.cpp

@@ -681,6 +681,8 @@ bool wxApp::ProcessIdle()
     event.SetEventObject(this);
     ProcessEvent(event);
 
+    wxUpdateUIEvent::ResetUpdateTime();
+    
     return event.MoreRequested();
 }