Translation for german

Still some TODO's, intent:
https://play.google.com/store/apps/details?id=org.telegram.messenger&reviewId=Z3A6QU9xcFRPRjlnTzdFMzg4SnBVQlRBNDFiOFZ3VXpIeW1UTWw0RkFKNDNWVFo0T3JqUDgxT045V18xak8wYXBHaVMxaUpCQ0FYOEdzZE9yb0d5b3N2cGs0


User should have possibiltiy to decide the language of the app.