Embed: display more consistent timestamps across protocols and correctly show seekable range
Embed: fix: don't force nonexistent forcePlayer value
Embed: when info.unixoffset is known, display clock time based timestamps
- fixes as a result of documentation, fixed secondaryVideo
- added muted option, changing tracks sets options.setTracks
- no positive values for startunix when live seeking
- dashjs tracks updated, videojs display tweaked
- fixes for track selection and live seeking