[test] silence a few more deprecation warnings in unittest_hooks self.session → cnx.

[session] call rollback in Connection.__exit__ If we just free the cnxset and clear the Connection, we're missing the pending operation's rollback_event callbacks, which may be needed for cleanup.

[devtools] pre_setup_database takes a Connection, not a Session

[source/native] cPickle is available in all supported pythons

devtools: deprecate .req_from_url Which uses .request() And instead provide .admin_request_from_url, which is a context manager yielding the request.

[tests] Add a webtest based TestCase class Closes #4002134

[tests] Move 'anonymous_allowed' property from CubicWebServerTC to CubicWebTC The effective set of the property on the config is now done later that before, ie at the end of CubicWebTC.init_config instead of before. It is believed not to have an impact on the test suites that uses `anonymous_allowed`. Related to #4002134

[compat] Remove imports of "any" and "all" from lgc (closes #4306044) They're builtin since python 2.5.

[css] Remove the `div` tag specification of the pendingDelete css rule The HTML tag was changed by e2f96b16c3bd from a div to a span without changing the css rule accordingly. Closes #4285248.

[cwvreg] cleanup the event manager when reloading modules Closes #3848995 The event manager callbacks are not cleaned during reloading. So the callback defined in the reloaded module appears twice (old and new version). This may cause problem when the old version is called.