Log Message:
youtube-dl: Update net/youtube-dl to 20180918

Changes:
version 2018.09.18

Core
+ [extractor/common] Introduce channel meta fields

Extractors
* [adobepass] Don't pollute default headers dict
* [udemy] Don't pollute default headers dict
* [twitch] Don't pollute default headers dict
* [youtube] Don't pollute default query dict (#17593)
* [crunchyroll] Prefer hardsubless formats and formats in locale language
* [vrv] Make format ids deterministic
* [vimeo] Fix ondemand playlist extraction (#14591)
+ [pornhub] Extract upload date (#17574)
+ [porntube] Extract channel meta fields
+ [vimeo] Extract channel meta fields
+ [youtube] Extract channel meta fields (#9676, #12939)
* [porntube] Fix extraction (#17541)
* [asiancrush] Fix extraction (#15630)
+ [twitch:clips] Extend URL regular expression (closes #17559)
+ [vzaar] Add support for HLS
* [tube8] Fix metadata extraction (#17520)
* [eporner] Extract JSON-LD (#17519)

version 2018.09.10

Core
+ [utils] Properly recognize AV1 codec (#17506)

Extractors
+ [iprima] Add support for prima.iprima.cz (#17514)
+ [tele5] Add support for tele5.de (#7805, #7922, #17331, #17414)
* [nbc] Fix extraction of percent encoded URLs (#17374)