jitterbuffer: unset DTS on output buffers
This is mostly to see how bad this would break our tests, and start a discussion about outputting buffers with a DTS in jitterbuffer.
As I understand it, once the buffers make it out of jitterbuffer, their arrival time shouldn't matter to anyone anymore, and I can observe when streaming a simple RTSP stream that we often end up with buffers that have a PTS lesser than their DTS, leading to issues in mp4mux. I can provide instructions to reproduce this specific problem, but I think the discussion should be more general :)
Edited by Mathieu Duponchelle