create an independent GdkWindow to behave nicely during reordering with
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.