youtube-dl 2018.01.27

Core

• [extractor/common] Improve _json_ld for articles
• Switch codebase to use compat_b64decode

• [compat] Add compat_b64decode

Extractors

• [seznamzpravy] Add support for seznam.cz and seznamzpravy.cz (#14102, #14616)

• [dplay] Bypass geo restriction

• [dplay] Add support for disco-api videos (#15396)

• [youtube] Extract precise error messages (#15284)
• [teachertube] Capture and output error message
• [teachertube] Fix and relax thumbnail extraction (#15403)

• [prosiebensat1] Add another clip id regular expression (#15378)

• [tbs] Update tokenizer url (#15395)
• [mixcloud] Use compat_b64decode (#15394)

• [thesixtyone] Remove extractor (#15341)