JS: caching static candidates for speed.
JS: internalize updateStaticCache() in Aulx.js

This in order to prevent export pollution.
JS: testing untokenizable contexts.
JS: Static properties from assignment expressions.

It's the start of including static type analysis.
JS: avoid error with `this` expressions in assignments.
JS: static property analysis does property completion.
JS: test static property completion.
Using ES6's Map when available and functional.
Don't pollute global object with Map.
JS: Avoid error with undefined properties in sandbox
JS: Accept parsers with callbacks.

Also, some documentation additions.
Demo, JS: Put the parser in Web Workers.