2015-01-13: JsSIP 0.6.0 released

Features:

• debug module.
• rtcninja module.
• Can renegotiate an ongoing session by means of a re-INVITE or UPDATE method (useful if the local stream attached to the RTCPeerConnection has been modified).
• Improved hold/unhold detection.
• New API options for UA#call() and RTCSession#answer().