Add new parser for ICU message patterns
Add `intl` as a devDependencies
Update tests for use with new parser.
Add baked-in format methods
Update `formatElementParser` with a third param to remove `this` usage
Add ES5 fallbacks for `[].forEach`, `[].some`, and `{}.keys`
Update tests for changes.
Remove ES5 fallback. Add in for-loop functions.
Remove default formatters from parser branch.
Remove old parser logic and regular expressions.
Update tests with changes.
Add in tests for completeness; adjust logic accordingly.
Add tests for parser coverage
Update documentation for clairty. `parseToken` now returns the token that was parsed.
Remove some white space.