This makes "git-ls-files --others --directory --ignored" behave
as documented and consequently also fixes "git-clean -d -X".
Previously, git-clean would remove non-excluded directories
even when using the -X option.
Signed-off-by: Michael Spang <mspang@uwaterloo.ca> Signed-off-by: Junio C Hamano <junkio@cox.net>