The default refresh interval of 1 day is woefully inadequate here;
users expect to be able to add the alias to their new account and
press the move button on their old account and have it work.
This allows callers to specify a maximum age before a refetch is
triggered. We set that to 5s for the move code, as a nice compromise
between Making Things Work and ensuring that this can't be used
to hammer a remote server
