[arte.tv:+7] Improve title extraction (Closes #3995)
[arte.tv] Remove unused import
[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)
fixes install target, fixes python-2.6 README.md target, invokes make test