Log Message:
youtube-dl: Update net/youtube-dl to 20180425

pkgsrc changes:
 - Adjust patches/patch-youtube__dl_postprocessor_ffmpeg.py to prefer ffmpeg3
   over ffmpeg2

Changes:
version 2018.04.25

Core
* [utils] Fix match_str for boolean meta fields
+ [Makefile] Add support for pandoc 2 and disable smart extension (#16251)
* [YoutubeDL] Fix typo in media extension compatibility checker (#16215)

Extractors
+ [openload] Recognize IPv6 stream URLs (#16136, #16137, #16205, #16246,
  #16250)
+ [twitch] Extract is_live according to status (#16259)
* [pornflip] Relax URL regular expression (#16258)
- [etonline] Remove extractor (#16256)
* [breakcom] Fix extraction (#16254)
+ [youtube] Add ability to authenticate with cookies
* [youtube:feed] Implement lazy playlist extraction (#10184)
+ [svt] Add support for TV channel live streams (#15279, #15809)
* [ccma] Fix video extraction (#15931)
* [rentv] Fix extraction (#15227)
+ [nick] Add support for nickjr.nl (#16230)
* [extremetube] Fix metadata extraction
+ [keezmovies] Add support for generic embeds (#16134, #16154)
* [nexx] Extract new azure URLs (#16223)
* [cbssports] Fix extraction (#16217)
* [kaltura] Improve embeds detection (#16201)
* [instagram:user] Fix extraction (#16119)
* [cbs] Skip DRM asset types (#16104)

version 2018.04.16

Extractors
* [smotri:broadcast] Fix extraction (#16180)
+ [picarto] Add support for picarto.tv (#6205, #12514, #15276, #15551)
* [vine:user] Fix extraction (#15514, #16190)
* [pornhub] Relax URL regular expression (#16165)
* [cbc:watch] Re-acquire device token when expired (#16160)
+ [fxnetworks] Add support for https theplatform URLs (#16125, #16157)
+ [instagram:user] Add request signing (#16119)
+ [twitch] Add support for mobile URLs (#16146)