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

Ah, so this is just for manual recovery -- the original intent of explicitly recording suite dirtiness was to explicitly record dirtiness for each operation that would dirty a suite, making publisher crashes automatically benign, and also reducing the performance penalty of uncondemned deletions to zero. This design is much less useful, but also easier and not terribly expensive to replace with the real thing later.