Localisation updates from https://translatewiki.net.

Change-Id: If056055a8ef035fe09915c51bb264af683bad4fc
Migrate to JSON i18n

Procedure per https://www.mediawiki.org/wiki/Manual:GenerateJsonI18n.php
with shim.

Change-Id: I320c5b88498b808c7b7c4c37ac537b5a4d61ce9b