Localisation updates from https://translatewiki.net.

Change-Id: I5e1f1ba50726d3b3a24d5d4bca387b2a83ceb7ef
Migrate to JSON i18n

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

Change-Id: Ie45e43181258db8340f50f112855fdc8b56a9d7f