With the usual "git" transport, a large-ish transfer with "git fetch" and
"git pull" give progress eye-candy to avoid boring users.  However, not
when they are reading from a bundle. I.e.

    $ git pull ../git-bundle.bndl master

This teaches bundle.c:unbundle() to give "-v" option to index-pack and
tell it to give progress bar when transport decides it is necessary.

The operation in the other direction, "git bundle create", could also
learn to honor --quiet but that is a separate issue.

Signed-off-by: Junio C Hamano <gitster@pobox.com>