Add language options

• Users can choose what language for email communications on registration
• email language changeable in profile settings
• When changing interface language, it sets a cookie named userLanguage for backend

added 173 commits

• 74f07f5a...96a24ec6 - 167 commits from branch pleroma:develop
• a5e861cd - Set userLanguage cookie when setting interface language
• d39de302 - Add config opts for email language
• 1d36ea5e - Add email language option to registration form
• 093c85d0 - Add English translation for language options
• 3633ea66 - Make lint happy
• f57171d7 - Make lint happy

Compare with previous version

merged

mentioned in commit a88abc7e

mentioned in commit 069cf3fa

mentioned in merge request !1526 (merged)

mentioned in merge request !1527 (merged)