With archiveDeletedAccountsFor set, a destroyed account's record is kept in
the fork subspace with its id, its DestroyAccount task is due at the end of
the period, and its shares are suspended both ways. Its addresses can't be
taken by new accounts, aliases, lists or masks. inbuxa:DeletedAccount/get
lists kept accounts to server and tenant administrators; /set restores one
with a new password (same id, task cancelled, shares reinstated) or destroys
it now. The destroy task also clears undelete's own records.
Acceptance test 14; test 16 written as the ignored undelete_compat.
jcoffey-dev