Re: git auto-repack is broken...

Thanks, Jeff, for the life-cycle chart.

A couple of ideas come to mind:
- When unpacking objects from a pack, it should be fine to set their
  date to that of the pack.  After all, they're at least that old.
- We could put unreferenced objects into packs whose date is the most
  recent of any of the contained objects.
- We could then group unreferenced objects into packs based on age,
  so their ages sould not be affected too much by the preceding
  operations.

That still produces a noticeable number of packs, which isn't good, but maybe it's better that keeping thousands of loose objects for a month...