These allows for some chance of avoiding extra save parses.
Also add wfDebug() call to mention the vary-* flag.
Bug: T226432
Depends-on: Idcd30a3fa3f7012dac76ce8bbf46625453ae331f
Change-Id: Id3bc207382aac90bd63df2d83d6334aae9b2477d
The following sniffs are failing and were disabled:
* MediaWiki.Usage.ForbiddenFunctions.popen
* MediaWiki.Usage.ForbiddenFunctions.proc_open
* MediaWiki.Usage.ForbiddenFunctions.shell_exec
Change-Id: I39e352194565a5526c1a8a34992c028fb305b03b