Set HICON and its parameters in one call

To avoid separate calls to SetSize() function after calling SetHICON() use newly implemented InitFromHICON() function which allows set HICON together with its parameters in one call.

include/wx/msw/icon.h

@@ -71,6 +71,7 @@ public:
 
     void SetHICON(WXHICON icon) { SetHandle((WXHANDLE)icon); }
     WXHICON GetHICON() const { return (WXHICON)GetHandle(); }
+    bool InitFromHICON(WXHICON icon, int width, int height);
 
     // create from bitmap (which should have a mask unless it's monochrome):
     // there shouldn't be any implicit bitmap -> icon conversion (i.e. no