Add NumberFormat.parse()
Allow NumberFormat constructor to take an optional currency name/symbol, so you can format for a particular locale without it dictating the currency, and also supply the currency symbols which we don't have yet.
Canonicalize locales more consistently, avoiding a number of problems if you use a non-canonical form.
For locales whose length is longer than 6 change “-” to “_” in position 3 when canonicalizing. Previously anything of length > 6 was left completely alone.
Add a “meaning” optional parameter for Intl.message to distinguish between two messages with identical text.
Handle two different messages with the same text.
Allow complex string literals in arguments (e.g. multi-line)