youtube-dl: Update net/youtube-dl to 20180409

Changes:
version 2018.04.09

Core
* [YoutubeDL] Do not save/restore console title while simulate (#16103)
* [extractor/common] Relax JSON-LD context check (#16006)

Extractors
+ [generic] Add support for tube8 embeds
+ [generic] Add support for share-videos.se embeds (#16089, #16115)
* [odnoklassniki] Extend URL regular expression (#16081)
* [steam] Bypass mature content check (#16113)
+ [acast] Extract more metadata
* [acast] Fix extraction (#16118)
* [instagram:user] Fix extraction (#16119)
* [drtuber] Fix title extraction (#16107, #16108)
* [liveleak] Extend URL regular expression (#16117)
+ [openload] Add support for oload.xyz
* [openload] Relax stream URL regular expression
* [openload] Fix extraction (#16099)
+ [svtplay:series] Add support for season URLs
+ [svtplay:series] Add support for series (#11130, #16059)

version 2018.04.03

Extractors
+ [tvnow] Add support for shows (#15837)
* [dramafever] Fix authentication (#16067)
* [afreecatv] Use partial view only when necessary (#14450)
+ [afreecatv] Add support for authentication (#14450)
+ [nationalgeographic] Add support for new URL schema (#16001, #16054)
* [xvideos] Fix thumbnail extraction (#15978, #15979)
* [medialaan] Fix vod id (#16038)
+ [openload] Add support for oload.site (#16039)
* [naver] Fix extraction (#16029)
* [dramafever] Partially switch to API v5 (#16026)
* [abc:iview] Unescape title and series meta fields (#15994)
* [videa] Extend URL regular expression (#16003)

version 2018.03.26.1

Core
+ [downloader/external] Add elapsed time to progress hook (#10876)
* [downloader/external,fragment] Fix download finalization when writing file
  to stdout (#10809, #10876, #15799)

Extractors
* [vrv] Fix extraction on python2 (#15928)
* [afreecatv] Update referrer (#15947)
+ [24video] Add support for 24video.sexy (#15973)
* [crackle] Bypass geo restriction
* [crackle] Fix extraction (#15969)
+ [lenta] Add support for lenta.ru (#15953)
+ [instagram:user] Add pagination (#15934)
* [youku] Update ccode (#15939)
* [libsyn] Adapt to new page structure

(leot)