STUN Discovery via JIngle Nodes

After a few months finally I got time to review and update Jingle Nodes Specifications. It is not yet submitted to xmpp.org, but you can sneak peak for now at: Jingle Nodes [Temp]
The most relevant change is that Jingle Nodes now will support STUN Tracking, which means that users can also share known STUN Servers. This is very handy and most of all, it is very easy to access STUN Servers as they not require authentication for Public IP Discovery.
After all, the most popular XMPP Servers in the market already offers embedded STUN Service (ejabberd STUN).
Google Talk Network also provides STUN Services, so they can also be shared through Jingle Nodes.

Another minor fixes and changes were also added.
Please fell free to read and submit critics and comments to it.