* Redesign landing page (again)

* Move login form in small version to the right column

* Display closed registrations message

* Add site setting for the hero image

* Fix test

* Increase spacing, maximum width, change call to action section

* Remove onboarding modal

* Welcome e-mail

* Send welcome e-mail after confirmation

* Remove obsolete translations

Serbian latin (sr-Latn) is generated automatically from Serbian (sr) translation. Also changed some wording in original (Serbian) translation.