Instead of basing Discovery of Support on the presence of a well-known pub-sub service node, an explicit Service Discovery feature is used. This prevents a scenario in which a non-administrative user flags 'opt-in' by creating the pub-sub node.
The XEP now mandates to include domain names of remote domains only after those remote domains advertise support for this XEP. This is intended as an opt-in mechanism.
Following discussion with Flow, MattJ and Jonas`, the data format was modified to:
- group connections under a remote domain
- use attributes instead of elements where appropriate
Remove ambiguity with regards to having more than one connection to a remote domain. With this update, each actual (eg TCP) connection is represented by a distinct `connection` element.
