4.3 Release
- [x] update deps
- [x] close old issues / tag new issues
- [x] test in latest Sketch
- [x] merge / close open PRs
- [x] update readme (remove Brainly refs)


- [x] shadow.html - text shadow doesn't work
- [x] shadow-dom.html - shadow content doesn't work
- [x] images.html - breaks