Merchandising cAPI components use JSON instead of a script in the DFP template 

Merchandising cAPI components (multiple, single and single - sponsored) stores now JSON instead of a script in a template. In the DFP we will now use the JSON format, load a proper module (CommercialComponent in this case) and fire 'create' method. The old method used ugly eval() on a script inside a creative template. 
use `this.params.type` a few times - might be better to store it as a property, e.g. `this.type = params.type`