[francetv] Force m3u8 formats extension to mp4 (Closes #3997)
[youtube] Only set language when necessary

We only need to set the language when we are using a login; otherwise it will always be English.
[pbs] Add support for tabbed frontline videos (Closes #4006)
[cinemassacre] Fix extraction (Closes #4008)
[thoughtworks] wistia support added
[francetv] Lower preference of direct links (Closes #4010, closes #3947)

Direct links fail with 403, fallback on f4m for now until further investigations.
[thoughtworks] wistia regex modified
Merge pull request #4009 from Dineshs91/thoughtworks

[thoughtworks] wistia support added
[generic/wistia] Improve regex
[funnyordie] Fix extraction (Closes #4011)