Adding a 'Come to CampSass' alert on the homepage

In two files, adding a small banner above the "Current release" with a (tasteful) ad for Camp Sass.
![screen shot 2014-03-20 at 11 03 46am](https://f.cloud.github.com/assets/108884/2475667/036d9a50-b05a-11e3-95e8-59095f41a979.png)