2006-05-09  Carlos Garnacho  <carlosg@gnome.org>

        * gtk/gtknotebook.c: create an independent GdkWindow to behave nicely
        during reordering with tab_labels with their own window, also use
        gtk_drag_set_icon_widget() for the DnD icon to avoid drawing garbage
        from offscreen regions. Closes bug #335707.
        (gtk_notebook_tab_space), (gtk_notebook_calculate_shown_tabs),
        (gtk_notebook_calculate_tabs_allocation): new functions,
        gtk_notebook_pages_allocate() functionality has been splitted into
        these.