Make notice dismissable

The "We Tried" notice that shows by default takes up most of the page
on smaller screens, so I've moved it into a notice and made it dismissible.

Before dismissal:
![screen shot 2014-01-17 at 3 58 40 pm](https://f.cloud.github.com/assets/408862/1945348/f2ada142-7fcb-11e3-8051-8628500f0878.png)

After dismissal:
![screen shot 2014-01-17 at 3 58 56 pm](https://f.cloud.github.com/assets/408862/1945349/f2b902c6-7fcb-11e3-8727-147e802941bc.png)