youtube-dl 2019.08.13

Core

• [downloader/fragment] Fix ETA calculation of resumed download (#21992)
• [YoutubeDL] Check annotations availability (#18582)

Extractors

• [youtube:playlist] Improve flat extraction (#21927)
• [youtube] Fix annotations extraction (#22045)

• [discovery] Extract series meta field (#21808)

• [youtube] Improve error detection (#16445)
• [vimeo] Fix album extraction (#1933, #15704, #15855, #18967, #21986)

• [roosterteeth] Add support for watch URLs

• [discovery] Limit video data by show slug (#21980)