[pkg] Use setuptools.find_packages()
We drop the custom get_packages() function in setup.py that used to look
for test files (not discovered automatically since test directories are
not packages) and replace it by explicit entries in MANIFEST.in.
.. _req_module:
:mod:`cubicweb.req`
===================
.. automodule:: cubicweb.req
.. autoexception:: FindEntityError
.. autoclass:: RequestSessionBase
:members: