Fixed some intersphinx references.

        version 2.2. This is a neat way to implement attributes whose usage

        resembles attribute access, but whose implementation uses method calls.

        See :func:`property`.

        See :class:`property`.

    queryset

        An object representing some set of rows to be fetched from the database.

      - ``modification``: last modification of the session, as a

        :class:`~datetime.datetime` object. Defaults to the current time.

      - ``expiry``: expiry information for the session, as a

        :class:`~datetime.datetime` object, an :func:`int` (in seconds), or

        :class:`~datetime.datetime` object, an :class:`int` (in seconds), or

        ``None``. Defaults to the value stored in the session by

        :meth:`set_expiry`, if there is one, or ``None``.

---------------

Python 2's `unicode`_ type was renamed :class:`str` in Python 3,

``str()`` was renamed :func:`bytes`, and `basestring`_ disappeared.

``str()`` was renamed :class:`bytes`, and `basestring`_ disappeared.

six_ provides :ref:`tools <string-handling-with-six>` to deal with these

changes.