WebRTC Javadoc 6.2.x

Hey Jim,

These are the edits for the chat-video portlet by Philippe Proulx of Savoir Faire. I made the initial edits we talked about and sent the revised Javadoc to Philippe for review. He tweaked a few things and added several new class descriptions.

Philippe preferred "Verifies" over "Listens" for the Listener classes, because they were better descriptive words for what was going on in the class. The updated Javadoc now represents the updated code from Philippe/Brian's recent work.

We had talked about only working in the EE repo due to CE-master's inconsistencies for Javadoc, but I found that the *6.2.x* branch for CE is identical to the *ee-6.2.x* branch for EE for these classes. Therefore, this pull request is for the *6.2.x* branch (you did not have a *6.2.x* branch to send this pr to, so I sent it to your *master*). Let me know if you'd like me to send this same Javadoc for EE as well. 

Thanks,
Cody