Merge features from dev to master
Features:
- Added the possibility to select multiple videos by specifying a range. Documentation for this has been added to the README file.
Fixes:
- Fixed no longer being able to authenticate for videos requiring an ETH login. To be precise: Something in the backend of video.ethz.ch changed, so the "Referer" header is now required when sending a POST request to acquire a cookie for "ETH" protected videos.