this fixes a bug where if the `editor` config is set to an unsupported
value there is a nil pointer error and the pad fails to render when
editing only, not on a new post.
This renders all requests for that user's posts, collections and related
ActivityPub endpoints with 404 responses.
While suspended, users may not create or edit posts or collections.
User status is listed in the admin user page
Admin view of user details shows status and now has a button to activate
or suspend a user.
GetCollections and GetPublishableCollections now take a hostname
parameter to allow setting the collecion hostname.
All collections used in memory now have their hostname set.
