Add two test cases in t7406 to ensure that the --merge/--rebase options
are ignored for "git submodule update" with new modules. These test that
a simple checkout is performed instead.
Signed-off-by: Spencer E. Olson <olsonse@umich.edu> Acked-by: Jens Lehmann <Jens.Lehmann@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>