Add --hls-use-mpegts option

When using the mpegts container hls vidoes can be played while being downloaded (useful if you are recording a live stream).
VLC and mpv play them file, but QuickTime doesn't.

youtube_dl/__init__.py

@@ -369,6 +369,7 @@ def _real_main(argv=None):
         'no_color': opts.no_color,
         'ffmpeg_location': opts.ffmpeg_location,
         'hls_prefer_native': opts.hls_prefer_native,
+        'hls_use_mpegts': opts.hls_use_mpegts,
         'external_downloader_args': external_downloader_args,
         'postprocessor_args': postprocessor_args,
         'cn_verification_proxy': opts.cn_verification_proxy,