Adding options for commercial capi multi component

This allows merchandising to select "Brought to you by", "Sponsored by" & "Supported by" from an option in the DFP template. This then adds the correct styles and label to the component as required.

![screen shot 2014-11-25 at 15 41 32](https://cloud.githubusercontent.com/assets/1303616/5185772/b43bcce8-74b9-11e4-96c0-e18a6cfb8240.png)

cc @Calanthe 

Part of @ironsidevsquincy brave new world.
It's used by the single component at the moment, removing it is tricky a it is set in the DFP template itself. Component does need to be tweaked to work as the multi one is set up to now but a separate pull request me thinks.