Safari and Firefox (Unified plan)

This is obsolute. Instead of multiple video tracks, multiple connection works well.

Problem on multiple video and audio tracks

In unified plan, the answer side can not add m line, which corresponds to the media track.

In the negotiation of WebRTC using SDP, Jicofo provide offer and client can only answer to it.

So, client can not increase number of tracks.

→ Modification of jicofo is needed.

JingleOfferFactory.java must be modifed.