With this, when we use a finer timebase than neccessary to store
durations the demuxer still knows what the original timebase was.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This generalizes the previous work on disposition printing.
Disposition flags are shown in a dedicated section, which should improve
output intellegibility, extensibility and filtering operations.
This breaks output syntax with the recently introduced disposition
printing.
