Fixed #7011 -- Clarified what User.is_active really means in the documentation.

    .. attribute:: models.User.is_active

        Boolean. Designates whether this account can be used to log in. Set this

        flag to ``False`` instead of deleting accounts.

        Boolean. Designates whether this user account should be considered

        active. Set this flag to ``False`` instead of deleting accounts.

        This doesn't control whether or not the user can log in. Nothing in

        the authentication path checks the ``is_active`` flag, so if you want

        to reject a login based on ``is_active`` being ``False``, it is up to

        you to check that in your own login view. However, permission checking

        using the methods like :meth:`~models.User.has_perm` does check this

        flag and will always return ``False`` for inactive users.

    .. attribute:: models.User.is_superuser