Voice and Video GSoC Project

[Maiku]

Since the last update, I've implemented my ideas as far as getting
libPurple to support any number of different combinations of voice and
video sessions. In doing so, I've managed to get audio, video, and
audio/video sessions all working. Refactoring made this much simpler.
I've also, for the most part, kept up with recent Jingle XEP changes.

At this time, the Jingle code still relies on chance for it to work.
There needs to be enough time between messages for Farsight to figure
out the candidates and codecs. I recently found out that it doesn't
much like it if you connect to a Jabber server run locally. The
message round-trip time is too short. So I need to add some code to
make Jingle aware of the transaction state.

I've also been able to, at least temporarily, fix the 5-7 second
delay, that Diego pointed out, which happens after you click accept.
It has to do with an issue in Farsight. The fix only works for RTP,
one-to-one sessions, but that's all we do now.

For those of you who wish to test the video portions, but have no
video device, I've added the "Video Test Source" option to the video
plugin preference. Hopefully, that will make it easier to test.

That's all for me, best get back to coding,
-Maiku