Update net/youtube-dl to 20160406.

Changes:
2016.04.06:
[*] Various bug fixes and improvements

2016.04.05:
[cbs] add base extractor
[movieclips] fix extraction
[camwithher] Add extractor
[cbsinteractive] Add support for ZDNet videos
[instagram:user] Fix extraction (fixes #9059)
[youtube] Add support for zwearz (Closes #9062)
[zdf] Extract subtitles (closes #9081)
[auroravid] Add extractor (Closes #9070)
[deezer] Fix extraction (Closes #9086)
[*] Various bug fixes and improvements

2016.04.01:
[nbc] add new extractor for csnne.com(#5432)
[tenplay] remove extractor(fixes #6927)
[voxmedia] Add new extractor(closes #3182)
[*] Various bug fixes and improvements

2016.03.27:
[twitter] Fix extraction (closes #8966)
[*] Various bug fixes and improvements

2016.03.26:
[*] Various bug fixes and improvements

2016.03.25:
[hbo] Add new extractor
[cda] Add new extractor for cda.pl
[biobiotv] Add extractor
[francetvinfo] Add support for france3-regions and strip title (Closes #7673)
[openload] Add new extractor (closes #8489)
Add extractor for thescene.com (closes #8929)
[youtube:live] Add extractor (Closes #8959)
[*] Various bug fixes and improvements

2016.03.18:
[thestar] Add new extractor(closes #5955)
[tv3] Add new extractor(closes #8059)
[utils] Add extract_attributes for extracting html tag attributes
[bravotv] Add new extractor(#4657)
[once] Add new format extractor
[*] Various bug fixes and improvements

(leot)