Add a test for the -G and -S pickaxe options and related options.
This test supports being run with GIT_TEST_LONG=1 to adjust the limit
on the number of commits from 1k to 10k. The 1k limit seems to hit a
good spot on git.git
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
