Changed offer generation to generate offer when negotiation is required and signaling state is stable.
Implement workaround for FF not supporting onnegotiationneeded.
Implemented offer/answer creation on renegotiationneeded event.
Implemented negotiation workaround for Firefox.
Add pc registry to usermedia to trigger media updates to all pcs where the usermedia stream is used.
Disable enableRenegotiationSupport per default to make the stuff mergeable.
Merge pulll request #138 from longsleep/renegotiation

* renegotiation:
  Disable enableRenegotiationSupport per default to make the stuff mergeable.
  Add pc registry to usermedia to trigger media updates to all pcs where the usermedia stream is used.
  Implemented negotiation workaround for Firefox.
  Implemented offer/answer creation on renegotiationneeded event.
  Implement workaround for FF not supporting onnegotiationneeded.
  Changed offer generation to generate offer when negotiation is required and signaling state is stable.