pexec: instead of closing stderr, redirect it to /dev/null
print a usage error if no options were specified
fix peertube links with no streaming playlists; make error reports better
don't crash when no video streams found
leave empty files if no audio (or video) stream is available
fix youtube http(s) links parsing
fix "quality" field comment
remove fps; harden/simplify json extraction
peertube: display sample rate and number of channels
better handling of "published" timestamp. make it work for PeerTube as well
fix crash when quality is nil
skip empty strings when printing info
add peertube support and fix description/etc