Commercial: advertisement feature front

Includes pulling in `HeadlineSans` font, only on articles/fronts which are advertisement features

Also update `guss`

![screen shot 2014-05-14 at 10 33 51](https://cloud.githubusercontent.com/assets/74132/2969230/e4a2ad4c-db4a-11e3-9f72-2630ff1882f3.png)