Tracker for discussed future PR

[zorkow]

• [x] Unify indentation to 2 spaces.
• [x] Add initialisation methods for packages to their configuration.
  • [ ] Generalise color package, newcommand etc structures.
  • [ ] Unicode cache as discussed in PR #263
• [ ] Mark optional parameters in jsdoc comments
• [x] Caligraphic to calligraphic everywhere
• [x] Move BBox.ts to utils directory
• [ ] Move to modern string composition
• [x] Change MathJax to mathjax in mathjax.js
• [x] Priorities for handlers as discussed in PR #222
• [x] Make annotations a dynamic menu. Possibly move these into contextmenu package. See PR #329
• [x] Make contexmenu a package that can be imported via a standard ES6 import.