This patch adds the ability to set a new identity_uri parameter.
It also deprecates the old auth_host, auth_port, auth_protocol,
and auth_admin_prefix parameters. Logic is in place so that
users of the deprecated settings should have a smooth upgrade
process and get deprecation warnings until they adopt the
new settings.
Change-Id: Ideefb4d824cbd5b4b83f9eb773a75e536e3458fb