[pyramid] Call repository's shutdown method atexit This way when run through a WSGI server (pserve, gunicorn, etc.) we make sure that the repository is properly shut down. In particular, this would wait for threads to terminate (otherwise, they'll be killed).

[querier] Turn repo.querier_cache_key into a private function of the querier module, only place where it's used.

[cleanup] Fix flake8 errors in web/application.py and associated test

[test] Simplify CWTC's init_authentication and assertAuthSuccess which shouldn't rely on removed .session attribute while it's not necessary and could be written in a simpler way.

[cleanup] Drop non sense sentence in docstring

[repo] Drop Session at last This is not used at all anymore.

Fix flake8 some errors

[test] Use existing reference to repo_source

[repo] Drop repo.new_session method we should not go through Session to create Connection anymore. This is unofficial API, no backward compat for now.

Stop using Session on the repository side Only expect session on web request, and let the web session/authentication managers provide them. Access to cnx.data, which used to return session data, is deprecated: there is no more access to session data from the repository side, and they should be access from req.session.data from the web side.