Quickly enable/disable AFTv5

Feature requirements: http://www.mediawiki.org/wiki/Article_feedback/Version_5/Feature_Requirements#Enable.2Fdisable_feedback_on_a_page

TL;DR:
* (if feedback disabled) "Request feedback" link in toolbox, on article page
* (if feedback disabled) Yellow box on special page with button to re-enable
* New "settings" in special page. When clicked, display link to enable/disable
* Links to enable/disable go to:
  * (admins) page?action=protect, where detailed permissions can be set
  * (editors) api call; will set permissions to aft-reader (enable) or aft-editor (disable)
* Refactored checks to verify if AFT should be displayed
  * Lottery now servers as the default value for page protection
    * No page protection set, lottery decides (lottery win = aft-reader, lottery lose = aft-noone)
    * Page protection set = overrides lottery (both enable or disable)
  * Unless disabled in page protection, whitelist categories will still enable AFTv5
  * Blacklist categories still override-disable all
* Grouped tipsies code into 1 method & made a change to hide "settings" link if there's no content

Change-Id: I7029a628ba724ba53f3aaebbf98e3d652c823464
Merge "Quickly enable/disable AFTv5"