[PATCH 0/4] Rediffed against the tip of git-pb tree

Petr, I am sending rediff against the tip of git-pb tree.  One
of the patches is not just rediff---the earlier version I failed
to add a couple of newly created files.

 [1/4] Add --author and --committer match to git-rev-list and git-rev-tree.
 [2/4] Tweak diff output further to make it a bit less distracting.
 [3/4] Implement git-checkout-cache -u to update stat information in the cache.
 [4/4] Trivial test harness fixes.