Code review comment for lp:~cjwatson/launchpad/db-archive-dirty

This is going to be heavily, heavily contended, bloat Archive massively, and cause most copies to fail. It probably makes sense to instead have a non-unique ArchiveDirtySuite or similar table, which each dirtying operation adds to. The publisher records all the IDs that were there when it started, and deletes those when it completes.