Localisation updates from https://translatewiki.net.

Change-Id: Ibb5016ad4e81d6f031e45e58454a643c968dec03
Remove unused $wgTitles

Change-Id: I4aff44723473a89a18feda14fbce93ac25c7d19e
Localisation updates from https://translatewiki.net.

Change-Id: Ia5d4983c128ee474a57ae07a2d33369d106ac09e
Migrate to JSON i18n

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

Change-Id: Ie0164fd5d101b1ab3cf9214f1854ae1360bae883
Remove zh-[sg|hk] in favour of zh-han[s|t]

Change-Id: Idcd5af52b27b9c5a9bfe496cb26f02062ae59019