Add (animated using css) snow to the dashboard.

Optionally, if you think this is too distracting or making it too hard
to read we can move this behind the widgets.

![12_15_14 at 12 49 34pm](https://cloud.githubusercontent.com/assets/769039/5441775/fe80eeba-8458-11e4-89c9-cbe16e25aadc.png)