Added dummy OnIdle to wxWindow in wxGTK; doc tweaks

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@1837 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/window.h

@@ -420,6 +420,9 @@ public:
 
     virtual void OnInternalIdle();
 
+    // For compatibility across platforms (not in event table)
+    void OnIdle(wxIdleEvent& WXUNUSED(event)) {};
+
     /* used by all classes in the widget creation process */
 
     void PreCreation( wxWindow *parent, wxWindowID id, const wxPoint &pos,