If you want your store to be able to auto- create users, then you can
implement these methods:
-=head24 auto_update_user( $authinfo, $c, $res )
+=head4 auto_update_user( $authinfo, $c, $res )
This method is called if the realm's auto_update_user setting is true.
-=head2 auto_create_user( $authinfo, $c )
+=head4 auto_create_user( $authinfo, $c )
This method is called if the realm's auto_create_user setting is true.