Fix for TextCtrl problem as reported by Vegh

Move definition of wxMenuItem to /gtk/menuitem.h
  Radical change of how to insert a child into a
    paren window. As C++ doesn't have any VMT in
    a class's consructor, I have to use a callback.
  Fixed culumn resizing bug in wxListCtrl
  Fixed menu height bug in MDI code


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@955 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/mdi.h

@@ -178,7 +178,6 @@ class wxMDIClientWindow: public wxWindow
     wxMDIClientWindow( wxMDIParentFrame *parent, long style = 0 );
     ~wxMDIClientWindow(void);
     virtual bool CreateClient( wxMDIParentFrame *parent, long style = wxVSCROLL | wxHSCROLL );
-    void AddChild( wxWindow *child );
 };
 
 #endif // __MDIH__