OF-443: No longer use the dialback namespace definition as a trigger to start dialback (but use the db:verify / db:result elements instead). When the reported version of the stream is absent (prevents compatibility issues with openfire before version 3.7.1) or smaller than one, nothing should be sent on the stream before a db:verify / db:result stanza is sent (no stream features, for example). This mimics old behaviour. This way, dialback appears to be triggered by the namespace definition in the stream (even though in actuality it's triggered by a child element) which makes things backwards compatible.

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@12837 b35dd754-fafc-0310-a699-88a17e54d16e