This provides a stable and simpler progress reporting mechanism that
updates progress as often as possible but accurately not updating more
than once a second.  The deltification phase is also made more
interesting to watch (since repacking a big repository and only seeing a
dot appear once every many seconds is rather boring and doesn't provide
much food for anticipation).
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NJunio C Hamano <junkio@cox.net>