ADEN-850 Remove wgAdDriverUseGptMobile* and clean up
ADEN-850 Rename ad_slots2 to ads_run, wikiamobile_ads_gpt_js to wikiamobile_ads_js
ADEN-850 Add a note about DartUrl and WikiaDartHelper
Merge pull request #3582 from Wikia/aden-850-clean-up-mobile-gpt

Aden 850 clean up mobile gpt