Move wxTopLevelWindow::SetShape() down to wxNonOwnedWindow.

Also add wxNonOwnedWindow for wxMSW (which previously simply typedef'd it to
wxWindow) and document this class now that it provides some user-visible
functionality.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@69364 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/toplevel.h

@@ -57,9 +57,6 @@ public:
 
     virtual void SetLayoutDirection(wxLayoutDirection dir);
 
-#ifndef __WXWINCE__
-    virtual bool SetShape(const wxRegion& region);
-#endif // __WXWINCE__
     virtual void RequestUserAttention(int flags = wxUSER_ATTENTION_INFO);
 
     virtual bool Show(bool show = true);