Only draw borders if wxSP_3DBORDER specified, as before

Added IsAppThemedEx which _really_ tells you if the app is
themed, and used it in wxRendererNative::GetDefault()


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@22432 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/uxtheme.h

@@ -310,6 +310,10 @@ public:
     wxUX_THEME_DECLARE(PFNWXUDRAWTHEMEPARENTBACKGROUND, DrawThemeParentBackground)
     wxUX_THEME_DECLARE(PFNWXUENABLETHEMING, EnableTheming)
 
+    // This calls IsAppThemed but also checks the commctrl.dll version
+    // for a more reliable answer.
+    bool IsAppThemedEx() ;
+
 private:
     // construcor is private as only Get() can create us and is also trivial as
     // everything really happens in Initialize()