R1:a9158d34d46a

Show commit audit status in repository history tables, including merge commit lists

Summary:
Fixes T6024. Ref T12121. Currently, we show build status in commit history tables; show audit status alongside it.

Also:

- Change the "Author/Committer" header to just "Author"; I think it's reasonably obvious what "x/y" means (if you can't guess, you can click the commit and likely figure it out) and this gives us a little more space.
- Make the audit list look more like the corresponding list in…