Add batch actions to the quiz editor.
This is a branch that I had locally for a long time. It contains tons of commits with improvements for the quiz editor. Most importantly, it adds a bunch of batch actions to the quiz editor, but is also adds:
- Moving question groups instead of separate slides. (To move separate slides from now on, use the CTRL or Command key)
- The Quiz Lint, which automatically checks the quiz for common mistakes and errors.
- Fullscreen button which renders the Quiz Editor in fullscreen.
It also fixes tons and tons of bugs, most noticeably:
- PDFs can be uploaded again.