Add community account to mailboxes, and self service password change

Add community account to mailboxes, and self service password change

Instead of just having pattern based permissions, also make it possible
to attach a community account to an individual mailbox. If this is done,
that account can then manage their own password without having pattern
based access, as a simple self-service. The only thing they can change
is the password, other attributes are still managed by the admins.