update libav to d4df02131b5522
playlist: set sent_end_of_q at playlist create

This fixes a race condition where sinks could get the end of queue
sentinel before decoding even started.

This solves a SIGFPE crash when encoder tries to encode a NULL frame
before encoding any frames before that.
better timestamp setting

Set the presentation time stamp on the frame and let the encoder figure out
the timestamps on the packets.
Merge branch 'master' into 2.x
Release 2.0.4