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/mac/carbon/window.cpp

@@ -1371,7 +1371,8 @@ void wxWindowMac::OnIdle(wxIdleEvent& event)
 {
     // This calls the UI-update mechanism (querying windows for
     // menu/toolbar/control state information)
-    UpdateWindowUI();
+    if (wxUpdateUIEvent::CanUpdate())
+        UpdateWindowUI();
 }
 
 // Raise the window to the top of the Z order