Bunch of GTK theme changes.

Make wxStatusBar use themes.
  SetStatusText() now uses Refresh() since I don't
    know why it shouldn't.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@15228 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk1/dcclient.cpp

@@ -1569,9 +1569,7 @@ void wxWindowDC::Clear()
 
     if (m_owner)
     {
-        int width,height;
-        m_owner->GetSize( &width, &height );
-        gdk_draw_rectangle( m_window, m_bgGC, TRUE, 0, 0, width, height );
+        m_owner->Clear();
         return;
     }