Duh.
This restores the ability to enter URLs without a scheme (and default to http), but still fail if the input is a search term.
It uses a helper method in the InfoExtractor class. The downloader will pick the requested formats using the bitrate in the info dict.
For some videos the resolution is not included in the url, we will need to look in the m3u8 manifest.
youtube-dl -j http://www.twitch.tv/fang_i3anger still fails though.
Fixes #3356