[db-api/configuration] simplify db-api and configuration so that all the connection information is in the repository url, closes #2521848 eg no more specific option of pyro ns host, group, etc. This also fixes broken ZMQ sources. Changes: * dropped pyro-ns-host, pyro-instance-id, pyro-ns-group from client side config, in favor of repository-uri. No migration done, supposing there is **no web-only config** in the wild. Also stop discovering the connection method through the repo_method class attribute of the configuration, varying according to the configuration class. This is a first step on the way to a simpler configuration handling. Notice those pyro options are still available for repository only / all-in-one configurations as they are needed to configure the pyro server. * stop telling connection method using ConnectionProperties, this is so boring. Also, drop _cnxtype from Connection and cnxtype from Session. The former is replaced by a is_repo_in_memory property and the later is totaly useless. * deprecate in_memory_cnx which becomes useless, use _repo_connect instead

# -*- 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 views/forms/actions/components for web ui"""