Log Message:
Update net/youtube-dl to 2016.06.18.1

pkgsrc changes:
- Use :S modifier exactly two times (instead of using the 'g'
  option) in PKGNAME to properly handle VERSION_DATEs with minor
  revisions. No other functional changes intended.

Changes:
2016.06.18*
-----------
[carambatv] add extractor
[nickde] add extractor

2016.06.16
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[*] misc bug fixes and improvements

2016.06.14
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[rockstargames] add new extractor
[*] misc bug fixes and improvements

2016.06.12
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[telewebion] add new extractor
[*] misc bug fixes and improvements

2016.06.11*
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[vidio] add extractor
[youku:show] add new extractor
[weibo] remove the extractor
[vulture] remove the extractor
[*] misc bug fixes and improvements

2016.06.03
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[seeker] add new extractor
[loc] add extractor
[*] misc bug fixes and improvements

2016.06.02
----------
[*] misc bug fixes and improvements

2016.05.30.2.*
--------------
[afreecatv] add new extractor
[WDR] various bug fixes and improvements
[*] misc bug fixes and improvements