Teach runstatus about --untracked

Actually, teach runstatus what to do if it is not passed; it should not list
the contents of completely untracked directories, but only the name of that
directory (plus a trailing '/').

[jc: with comments by Jeff King to match hide-empty-directories
 behaviour of the original.]

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

git-commit.sh

@@ -82,7 +82,8 @@ run_status () {
   esac
   git-runstatus ${color} \
                 ${verbose:+--verbose} \
-                ${amend:+--amend}
+                ${amend:+--amend} \
+		${untracked_files:+--untracked}
 }
 
 trap '