git p4: revert deleted files after submit cancel

git p4: revert deleted files after submit cancel

The user can decide not to continue with a submission,
by not saving the p4 submit template, then answering "no" to
the "Submit anyway?" prompt.  In this case, be sure to
return the p4 client to its initial state.

Deleted files were not reverted; fix this and test all cases.

Signed-off-by: Pete Wyckoff <pw@padd.com>
Acked-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>