_parse_ism_formats was extended into _parse_ism_formats_and_subtitles;
all direct users were updated, though _extract_ism_formats was left
as a compatibility wrapper.
The SSTR downloader was also modified in order to prepare for muxing
subtitle streams, although no support for any subtitle codecs was
added in this commit.
_extract_m3u8_formats is renamed to _extract_m3u8_formats_and_subtitles
and extended to handle subtitle tracks instead of skipping them;
a wrapper with the old name is provided for compatibility.
_parse_m3u8_formats is likewise renamed and extended, but without adding
the compatibility wrapper; the test suite is adjusted to test the enhanced
method instead.
Closes#121
TODO:
* Add an option for the user to specify newest/popular and max number of comments
* Refactor the download code and generalize with TabIE
* Parse time_text to timestamp
* All modules and binary names are changed
* All documentation references changed
* yt-dlp no longer loads youtube-dlc config files
* All URLs changed to point to organization account
Co-authored-by: Pccode66
Co-authored-by: pukkandan