Capitalize JavaScript

Change-Id: I96c4d87713cfeeae2ea028e904cc1e8e9d32f907
Replace usage of deprecated Title::escapeLocalURL()

Change-Id: I4e98a432404293122cfe09d03bda5e41b123fca3
Migrate to JSON i18n

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

Change-Id: Ib9e013a58c2849b8c421e2b1e9e3c3faf5d32ad2