[clean_session] revert itervalues usage from 0bb18407c053
self.close(session) changes the self._sessions content. We need to create a full
list of value before starting closing them.
Additional services
===================
In this chapter, we introduce services crossing the *web -
repository - administration* organisation of the first parts of the
CubicWeb book. Those services can be either proper services (like the
undo functionality) or mere *topical cross-sections* across CubicWeb.
.. toctree::
:maxdepth: 2
undo