Localisation updates from https://translatewiki.net.

Change-Id: Ic23e4671fe814ef69df17ff2676d8d64cd3d7081
Migrate to JSON i18n

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

Change-Id: Ia23fa73bf82596ef8458891212aadbdf998c3f62