git-am: implement --reject option passed to git-apply

With --reject, git-am simply passes the --reject option to git-apply and thus
allows people to work with reject files if they so prefer.

Signed-off-by: martin f. krafft <madduck@madduck.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/git-am.sh b/git-am.sh
index e20dd88..b1c05c9 100755
--- a/git-am.sh
+++ b/git-am.sh
@@ -19,6 +19,7 @@
 directory=      pass it through git-apply
 C=              pass it through git-apply
 p=              pass it through git-apply
+reject          pass it through git-apply
 resolvemsg=     override error message when patch failure occurs
 r,resolved      to be used after a patch failure
 skip            skip the current patch
@@ -168,6 +169,8 @@
 		git_apply_opt="$git_apply_opt $(sq "$1=$2")"; shift ;;
 	-C|-p)
 		git_apply_opt="$git_apply_opt $(sq "$1$2")"; shift ;;
+	--reject)
+		git_apply_opt="$git_apply_opt $1" ;;
 	--)
 		shift; break ;;
 	*)