BangleJS 2 not respecting 12h locale setting

For Time Zone, it gets set up automatically if you set the time with the app loader, but it's handy for things like the GPS where the time always comes in UTC, so if you ever want to update the time from GPS then it'll ensure it's still set right.

There's an issue open for the 12/24 hour settings: https://github.com/espruino/BangleApps/i­ssues/892

It seems some apps do implement it manually, but the locale module should really handle it.