Person.account_status and friends must go

After the auth-person-split branches, Person.account_status, account_status_comment, openid_identifier and password attributes become properties, proxying for Account attributes. They just exist to reduce the impact of the auth-person-split branch on existing code.

These properties should be removed, and call sites changed to use the Account attributes directly. This may involve changing the security declarations on Account as it is currently very tight (and Person too lose).