fat controller

Added a controller (slot-controller.js) module to orchestrate client-side insertion of content (e.g. ads, related stories, commercial) into articles:
- possible slots are generated server-side as divs within the article body
- javascript module (slot-controller.js) handles placement of content within these slots
- various rules/constraints to ensure content is inserted in appropriate places

Added an ab-test to pull videos/galleries out of the story package and insert them inline in the article.


![image](http://i201.photobucket.com/albums/aa310/woody938/gifs/Boss466.gif)