Support interoperability between Chrome and Firefox

[modeswitch]

Right now we're only able to connect browsers of the same vendor. There's some work to be done to support connections between different browsers.

[modeswitch]

Waiting for https://code.google.com/p/webrtc/issues/detail?id=1408&q=binary&colspec=ID%20Pri%20Mstone%20ReleaseBlock%20Area%20Status%20Owner%20Summary

[luser]

This got fixed in browsers, works after my refactor in 35aa612