[vh1] Add new extractor (#2072)
[vh1] use standard sort (#2072)
added spiegel.tv
cleanup
use provided function to get JSON
tabs as spaces
[Spiegeltv] skip rtmp download to pass Travis test build
[Spiegeltv] remove the md5 field to pass Travis test build
[yahoo] improve thumbnail extraction
Merge pull request #3047 from pulpe/yahoo_thumb

[yahoo] improve thumbnail extraction
[TagesschauIE] Add extractor for tagesschau.de (fixes #3049)
[TagesschauIE] Remove unused import
[TagesschauIE] Add note to 2nd _download_webpage
[youtube:playlist] Fix mixes extraction (fixes #3051)

The username seems to be empty now.
[TagesschauIE] Fix possible error if quality is not defined
[TeacherTubeIE] Add extractor for teachertube.com videos + classrooms (fixes #3046)
[naver] Add rtmp formats (fixes #3054)
[naver] Modernize
[xvideos] Capture and output inline error if any
[xvideos] Replace test