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.
format|filename=tests/data/ffprobe-test.nut|nb_streams=3|format_name=nut|start_time=0.000000|duration=11.960000|size=1054625|bit_rate=705434|tag:title=ffprobe test file|tag:comment='A comment with CSV, XML & JSON special chars': <tag value="x">|tag:comment2=I ♥ Üñîçød€
format,tests/data/ffprobe-test.nut,3,nut,0.000000,11.960000,1054625,705434,ffprobe test file,"'A comment with CSV, XML & JSON special chars': <tag value=""x"">",I ♥ Üñîçød€