----------------
- Implement ``expires`` and ``expired`` on ``cone.sql.ugm.UserBehavior``.
Extend ``cone.sql.ugm.UgmBehavior`` by ``user_expires_attr`` which
enables used expiration support.
[rnix]
- Add ``TestSQLSessionFactory`` and set to ``cone.sql.session_factory`` in
``SQLLayer.init_sql`` if not present.
[rnix, toalba]