2nd attempt at MDI in wxMotif, using wxNotebook this time (still some probs).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@1034 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/motif/frame.h

@@ -155,6 +155,7 @@ public:
   inline WXWidget GetWorkAreaWidget() const { return m_workArea; }
   inline WXWidget GetClientAreaWidget() const { return m_clientArea; }
   inline WXWidget GetTopWidget() const { return m_frameShell; }
+  inline WXWidget GetMainWindowWidget() const { return m_frameWidget; }
 
   // The widget that can have children on it
   WXWidget GetClientWidget() const;