-* PostfixadminDb can be made a plugin -- prune just won't work without
- it.
-
-* Error reporting sucks, and when a domain or account doesn't exist we
- should be able to say so. The describe_domain/account functions
- should also work better. Depending on what we do in the first bullet
- point, they could either return a list of names, or
- NotImplementedError.