This patch completely replaces the previous versions of our notebook patch
(gtk-hamann_jeske-980130-0 / gtk-hamann_jeske-980211-0). 

New in this patch :

- notebook now supplies a popup menu for fast page switching
- added gtk_notebook_{prepend|insert|append}_page_menu.
  These functions have an extra parameter GtkWidget *menu_label,
  which is used as popup menuitem 	 
- testgtk notebook sample has been changed accordingly

The patch is against the cvs - tree.
