In a following commit, we will make it possible to separate objects in
different packfiles depending on a filter.
To make sure that the right objects are in the right packs, let's add a
new test-tool that can display which packfile(s) a given object is in.
Let's also make it possible to check if a given object is in the
expected number of packfiles with a `--check-count <n>` option.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>