Fix Binary on python < 2.7.4 (closes #10593811)
Before the fix for http://bugs.python.org/issue10211 we can't pass a
buffer object to BytesIO, so keep using StringIO in that case. And
because StringIO is an old-style class, we can't use super().
.. _req_module:
:mod:`cubicweb.req`
===================
.. automodule:: cubicweb.req
.. autoexception:: FindEntityError
.. autoclass:: RequestSessionBase
:members: