basic webrtc scaffolding

This isn't the cleanest code, but it's something we can clean up and hack on. It doesn't work, and I'm not sure what broke, but need to just dig into this. It's not really *that* much code to do the whole WebRTC thing but it's a little complicated.

Need to convert the client-side js file into a require.js module too. I figure we can merge early and repent later.