Drop most of deprecated code As in previous changesets, most code has been deprecated since a very long time. This changeset concerns "core" cubicweb modules (e.g. "server", "appobjects") for which it's not easy to handle change atomically. In cubicweb/server/querier.py, we adjust empty_rset() function as a result of "rqlst" argument of ResultSet being dropped. (There was no use of the keyword argument anyways.)