Fixes
- Fixed #2122 - Focusable HTML5 video
- Fixed #2128 - Missing smallBtn on mobile
- Fixed #2096 - autoStart fullscreen AND slideshow
- Fixed #2097 - German translation
- Fixed #2132 - Youtube fullscreen
Improvements
- Captions now have linear-gradient background (instead of background image for pseudo element) and can have max-height and vertical scrollbar;
- Improved design for phones having the notch (https://webkit.org/blog/7929/designing-websites-for-iphone-x/)