Code review comment for lp:~wgrant/launchpad/observer-db

I think s/Permission/Grant/ will avoid some confusion.

This looks like what we discussed. Cool. Worth nothing I think is some more intent.
E.g. for artifacts mention that more types should be added there rather than in parallel tables.

Stuart: the idea here is that reporting is simple: one table supplies all the grants made to a private project/distro. Rather than a constantly evolving set of unions, this provides a single (indirect) level in the DB : *and* lets us query and report grants without accessing the granted-on objects [at least at this point]).

+1 from me but please get Stuarts ok before landing.