Replace deprecated WebRequest::getFileSize()

Change-Id: I37f3d4e5c43a456ed033b7b502ef5fcf61e69daa
Replace usage of deprecated Title::escapeLocalURL()

Change-Id: I13d932a36f3e9057a114bad67aa38319b1ef089c
Merge "Replace usage of deprecated Title::escapeLocalURL()"
Migrate to JSON i18n

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

Change-Id: If18f3f5da28250ef932a91990eb72cd600fd37b3