[connection] eliminate ClientConnection leftovers * in the documentation * in the docstrings * in code notations (e.g. clt_cnx -> cnx) Related to #3837233. From now, there should be just one ClientConnection left in repoapi.py.

# -*- coding: utf-8 -*-
# copyright %(year)s %(author)s, all rights reserved.
# contact %(author-web-site)s -- mailto:%(author-email)s
#
%(long-license)s
"""%(distname)s repository side views, usually for notification"""