With the commit of D6854 we are using just the international fonts. But this means that we still have a "Translation" checkbox in Preferences, but it does nothing useful.
This patch removes that checkbox and simplifies this area of Preferences.
Once applied you will see that there is now an "International" section and you can always easily change the language. Default is "English" and with that chosen the other options for translating tooltips, etc are cleared and disabled.
After selecting Japanese all options are enabled and turned on. That way the simple change of language has the most affect. For example, since Translate Interface is enabled immediately it means that all these other options are labeled correctly. It also means that we could put just the language list on the Splash screen and not have to include all the other checkboxes.