This correct the stop point for demuxing with -vcodec copy and -t as well as
packet interleaving. (we already diddrop packets but kept demuxing them
for too long due to opts being wrong)
the change to ffm is due to 2 packets with timestamp 0 being stored
in different order.


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@21626 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b