made default background colour BTNFACE (so that panels don't have to erase their background explicitly); removed now unneeded SetBackgroundColour() in wxDialog which now has default bg colour and restored one in wxFrame which now has a non default one

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@30564 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/frame.cpp

@@ -192,6 +192,8 @@ bool wxFrame::Create(wxWindow *parent,
     if ( !wxTopLevelWindow::Create(parent, id, title, pos, size, style, name) )
         return false;
 
+    SetBackgroundColour(wxSystemSettings::GetColour(wxSYS_COLOUR_APPWORKSPACE));
+
 #if defined(__SMARTPHONE__) && defined(__WXWINCE__)
     SetLeftMenu(wxID_EXIT, _("Done"));
 #endif