Internationalization (Revision #2)

- initial interface language is obtained from the OS

- every text string visible to the user must be localized

Options

- select interface language

- language change requires restart

Testing: add -Di18n.test.mode=1 to the list of JVM options.  Internationalized prompts will be marked with a bullet point.  Make sure there are no u2022 symbols in the preferences, as it indicates incorrect implementation.