* grub-core/commands/menuentry.c (grub_normal_add_menu_entry): New
parameter submenu. All users updated.
* grub-core/normal/main.c (free_menu): Rename to ...
(grub_normal_free_menu): ... this. Made global.
* grub-core/normal/menu.c (grub_menu_execute_entry): Open new context
if requested.
* grub-core/normal/menu_entry.c (screen): New field submenu.
(make_screen): Set submenu.
(run): Open new context if requested.
* include/grub/menu.h (grub_menu_entry): New field submenu.
* include/grub/normal.h (grub_normal_free_menu): New proto.