- The language and BCP need to be in-sync
- Existing code was inconsistent in setting things, which is why
you could get through the locale page without setting a locale
(at all) or it would keep English in spite of picking Germand on
the welcome page.
- Patch tests to use that API.
- Allow split-setting of the language and formats
- Test new constructors
- Since fromLanguageAndLocation can handle empty localeGen
lists just fine, skip all the weird checks that return
invalid guessed locale configurations.