Separate twisted-specific configuration from WebConfigurationBase class This is in preparation of dropping the Twisted web server backend. We thus draw a clearer line between what's specific to twisted from what's generic by moving WebConfigurationBase class into cubicweb/web/webconfig.py and only keeping twisted-related in AllInOneConfiguration (still living in cubicweb/etwist/twconfig.py).

.. _req_module:

:mod:`cubicweb.req`
===================

.. automodule:: cubicweb.req

    .. autoexception:: FindEntityError

    .. autoclass:: RequestSessionBase
        :members: