Removing banner advertising hackathons from landing page.

Changes: 

Deleted html block that contained announcement
Deleted less block that styled aforementioned announcement
Moved the dark green border back to above the quote, life is as it should be. 

![screen shot 2013-10-11 at 8 25 01 am](https://f.cloud.github.com/assets/1319950/1315635/60f7dc3e-3289-11e3-8336-37744208432a.png)