BugId:98734 - Preparations for ads in head test (backport from dev)

Conflicts:
	extensions/wikia/AdEngine/AdEngine2Controller.class.php
	extensions/wikia/AdEngine/js/AdEngine2.run.js
Merge pull request #472 from Wikia/release-150-bug-98734-adsinhead-test

BugId:98734 - Preparations for ads in head test (backport from dev)