* Create `FFmpegPostProcessor.real_run_ffmpeg` that can accept multiple input/output files along with switches for each
* Rewrite `cli_configuration_args` and related functions
* Create `YoutubeDL._ensure_dir_exists` - this was previously defined in multiple places
* Option `--concurrent-fragments` (`-N`) to set the number of threads
Related: #165
Known issues:
* When receiving Ctrl+C, the process will exit only after finishing the currently downloading fragments
* The download progress shows the speed of only one thread
Authored by shirt-dev
* Fix error when there is no `protocol` in `info_dict`
* Move HLS byte range detection to `Aria2cFD` so that the download will fall back to the native downloader instead of ffmpeg
* Fix bug with getting no fragments in DASH
* Convert `check_results` in `can_download` to a generator
* 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
