Ve 566 add wikia video

https://wikia-inc.atlassian.net/browse/VE-566

Adding ability to add premium videos and local videos via media tools 

Examples: 
video.wikia.com/wiki/File:PremiumVideoTitle
localwikia.wikia.com/wiki/File:LocalVideoTitle

Also adds support for wgAllowNonPremiumVideos.

@kenkouot @kflorence @BladeBronson @inez @saipetch @garthwebb