git-fetch: more terse fetch output

git-fetch: more terse fetch output

This makes the fetch output much more terse and prettier on a 80 column
display, based on a consensus reached on the mailing list.  Here's an
example output:

Receiving objects: 100% (5439/5439), 1.60 MiB | 636 KiB/s, done.
Resolving deltas: 100% (4604/4604), done.
From git://git.kernel.org/pub/scm/git/git
 ! [rejected]        html -> origin/html  (non fast forward)
   136e631..f45e867  maint -> origin/maint  (fast forward)
   9850e2e..44dd7e0  man -> origin/man  (fast forward)
   3e4bb08..e3d6d56  master -> origin/master  (fast forward)
   fa3665c..536f64a  next -> origin/next  (fast forward)
 + 4f6d9d6...768326f pu -> origin/pu  (forced update)
 * [new branch]      todo -> origin/todo

Some portions of this patch have been extracted from earlier proposals
by Jeff King and Shawn Pearce.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>