Applied John L's patches for curson scaling, image resizing

without scaling and the art provider resize bitmap patch.
    I'll look into adapting the generic file dialog to it.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@32598 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gdicmn.h

@@ -346,6 +346,8 @@ public:
     wxSize GetSize() const { return wxSize(width, height); }
     void SetSize( const wxSize &s ) { width = s.GetWidth(); height = s.GetHeight(); }
 
+    bool IsEmpty() const { return (width <= 0) || (height <= 0); }
+
     wxPoint GetTopLeft() const { return GetPosition(); }
     wxPoint GetLeftTop() const { return GetTopLeft(); }
     void SetTopLeft(const wxPoint &p) { SetPosition(p); }