youtube-dl 2018.12.31

Extractors

• [bbc] Add support for another embed pattern (#18643)
• [npo:live] Add support for npostart.nl (#18644)

• [beeg] Fix extraction (#18610, #18626)
• [youtube] Unescape HTML for series (#18641)

• [youtube] Extract more format metadata

• [youtube] Detect DRM protected videos (#1774)
• [youtube] Relax HTML5 player regular expressions (#18465, #18466)
• [youtube] Extend HTML5 player regular expression (#17516)

• [liveleak] Add support for another embed type and restore original
  format extraction
• [crackle] Extract ISM and HTTP formats
• [twitter] Pass Referer with card request (#18579)

• [mediasite] Extend URL regular expression (#18558)

• [lecturio] Add support for lecturio.de (#18562)
• [discovery] Add support for Scripps Networks watch domains (#17947)