support for parsing extended #EXTM3U header

[johnyxpro]

Hi,
This pull request add the support for parsing extended #EXTM3U header, for extended M3U playlists with custom attrubutes.

See:
https://github.com/AlexanderSofronov/iptv.example/blob/master/README.md
https://vip-tv.online/forum/68-664-1
https://vk.com/wall278393568_10115

[bbayles]

For what it's worth, I think this type of parsing is far enough from RFC 8216 and its descendants to recommend using a different library.

[davemevans]

The title references #EXTM3U, but the code changes the #EXTINF parser.

Extended #EXTINF parsing is already well supported by using a custom tag parser to override builtin parsing: https://github.com/globocom/m3u8#custom-tags

[johnyxpro]

The title references #EXTM3U, but the code changes the #EXTINF parser.

Extended #EXTINF parsing is already well supported by using a custom tag parser to override builtin parsing: https://github.com/globocom/m3u8#custom-tags

Yes you are right. Unfortunately, there is a bit of confusion with the title.
My pull request makes a small change (literally 1 line) to the #EXTINF parser which causes most iptv playlists to parse fine without errors and without involving custom tag parsers