Made MSW wxSpinCtrl emit UPDATE event when validating

the value in the text field upon kill focus.
 Documented this behaviour.
 This is in line with the GTK+ control.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@41316 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/spinbutt.h

@@ -61,7 +61,7 @@ protected:
    virtual wxSize DoGetBestSize() const;
 
    // ensure that the control displays a value in the current range
-   void NormalizeValue() { SetValue(GetValue()); }
+   virtual void NormalizeValue();
 
 private:
     DECLARE_DYNAMIC_CLASS_NO_COPY(wxSpinButton)