Add a new action for interactive git-clean: filter by pattern. When the
user chooses this action, user can input space-separated patterns (the
same syntax as gitignore), and each clean candidate that matches with
one of the patterns will be excluded from cleaning. When the user feels
it's OK, presses ENTER and backs to the confirmation dialog.
Signed-off-by: Jiang Xin <worldhello.net@gmail.com> Suggested-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>