Changelog: Add 10bit spp

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
lavf/concatdec: handle NOPTS start_time.

Fix trac ticket #3598.

Signed-off-by: Nicolas George <george@nsup.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>