Rewrite menu using a new method `list_and_choose`, which is borrowed
from `git-add--interactive.perl`. We will use this framework to add
new actions for interactive git-clean later.
Please NOTE:
* Method `list_and_choose` return an array of integers, and
* it is up to you to free the allocated memory of the array.
* The array ends with EOF.
* If user pressed CTRL-D (i.e. EOF), no selection returned.
Signed-off-by: Jiang Xin <worldhello.net@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>