Do git reset --hard HEAD when using git rebase --skip

When you have a merge conflict and want to bypass the commit causing it,
you don't want to care about the dirty state of the working tree.

Also, don't git reset --hard HEAD in the rebase-skip test, so that the
lack of support for this is detected.

Signed-off-by: Mike Hommey <mh@glandium.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-rebase.sh

@@ -157,6 +157,7 @@ do
 		exit
 		;;
 	--skip)
+		git reset --hard HEAD || exit $?
 		if test -d "$dotest"
 		then
 			git rerere clear