Log Message:
Update net/youtube-dl to 20170320.

Changes:
version 2017.03.20

Core
+ [YoutubeDL] Allow multiple input URLs to be used with stdout (-) as
  output template
+ [adobepass] Detect and output error on authz token extraction (#12472)

Extractors
+ [bostonglobe] Add extractor for bostonglobe.com (#12099)
+ [toongoggles] Add support for toongoggles.com (#12171)
+ [medialaan] Add support for Medialaan sites (#9974, #11912)
+ [discoverynetworks] Add support for more domains and bypass geo restiction
* [openload] Fix extraction (#10408)

version 2017.03.16

Core
+ [postprocessor/ffmpeg] Add support for flac
+ [extractor/common] Extract SMIL formats from jwplayer

Extractors
+ [generic] Add forgotten return for jwplayer formats
* [redbulltv] Improve extraction

version 2017.03.15

Core
* Fix missing subtitles if --add-metadata is used (#12423)

Extractors
* [facebook] Make title optional (#12443)
+ [mitele] Add support for ooyala videos (#12430)
* [openload] Fix extraction (#12435, #12446)
* [streamable] Update API URL (#12433)
+ [crunchyroll] Extract season name (#12428)
* [discoverygo] Bypass geo restriction
+ [discoverygo:playlist] Add support for playlists (#12424)

version 2017.03.10

Extractors
* [generic] Make title optional for jwplayer embeds (#12410)
* [wdr:maus] Fix extraction (#12373)
* [prosiebensat1] Improve title extraction (#12318, #12327)
* [dplayit] Separate and rewrite extractor and bypass geo restriction (#12393)
* [miomio] Fix extraction (#12291, #12388, #12402)
* [telequebec] Fix description extraction (#12399)
* [openload] Fix extraction (#12357)
* [brightcove:legacy] Relax videoPlayer validation check (#12381)