Commercial: Masterclasses high relevance component

Placeholder for Masterclasses high relevance component

Also ability to force a high relevance on article - append, e.g., `#commercial-component-high=masterclassesHigh`

![1252519743_top-model](https://cloud.githubusercontent.com/assets/74132/2901783/12bcd74a-d5db-11e3-9e81-6be0aa3932c8.gif)