Was no longer needed due to only being there to perform
language extension for de_informal but now this is done by crowdin
instead so it's redundant. Same goes for checking and formatting
scripts.
Also removed comment advising deletion form settings.php language list
since this is now auto-copied to languages anyway.
Related to #1261
Extended the base Laravel translation system to
allow a locale to be based upon another.
Also adds functionality to take base & fallback locales into account when fetching
an array of translations.
Related to work done in #1159
