New topbar design

This is @snconnolly's suggestions.

### Home Page
![screen shot 2014-10-04 at 12 18 36 pm](https://cloud.githubusercontent.com/assets/230476/4516560/e792b73a-4bfd-11e4-8296-3a8b74557988.png)

### When user is not logged in
![screen shot 2014-10-04 at 12 18 48 pm](https://cloud.githubusercontent.com/assets/230476/4516561/e7936f86-4bfd-11e4-8150-7f187e482b98.png)

### When user is logged in
![screen shot 2014-10-04 at 12 18 19 pm](https://cloud.githubusercontent.com/assets/230476/4516559/e7899f9c-4bfd-11e4-8357-499bbf7865d3.png)