youtube-dl 2021.04.17

Core

• [utils] Add support for experimental HTTP response status code
  308 Permanent Redirect (#27877, #28768)

Extractors

• [lbry] Add support for HLS videos (#27877, #28768)

• [youtube] Fix stretched ratio calculation
• [youtube] Improve stretch extraction (#28769)
• [youtube:tab] Improve grid extraction (#28725)

• [youtube:tab] Detect series playlist on playlists page (#28723)
• [youtube] Add more invidious instances (#28706)

• [pluralsight] Extend anti-throttling timeout (#28712)
• [youtube] Improve URL to extractor routing (#27572, #28335, #28742)

• [maoritv] Add support for maoritelevision.com (#24552)
• [youtube:tab] Pass innertube context and x-goog-visitor-id header along with
  continuation requests (#28702)

• [mtv] Fix Viacom A/B Testing Video Player extraction (#28703)

• [pornhub] Extract DASH and HLS formats from get_media end point (#28698)

• [cbssports] Fix extraction (#28682)
• [jamendo] Fix track extraction (#28686)
• [curiositystream] Fix format extraction (#26845, #28668)