Draw a multiple choice menu using `list_and_choose` to select items
to be deleted by numbers.
User can input:
* 1,5-7 : select 1,5,6,7 items to be deleted
* * : select all items to be deleted
* -* : unselect all, nothing will be deleted
* : (empty) finish selecting, and return back to main menu
Signed-off-by: Jiang Xin <worldhello.net@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>