Notes:
Translations for all languages in preferences' drop-down should be written in native language not depending from current locale. As for example, you can take Youtube language settings at the bottom of the screen. And user can choose a language he can actually read.
As all localisation strings go to "en" as a fallback, we can just remove locale translations from all localization files except "en"".
Sergey Karavay
Vojta Svoboda
Jens Herlevsen
Jérémy Gaulin
Samuel Georges
krisawzm
Wuri Nugrahadi