Style the general dashboard icons

Before:
![screenshot from 2014-07-31 16 52 19](https://cloud.githubusercontent.com/assets/514785/3766215/c2fc1e5c-18c2-11e4-927b-0ac4b2e9fc46.png)

After:
![screenshot from 2014-07-31 16 55 32](https://cloud.githubusercontent.com/assets/514785/3766217/ca48b1fc-18c2-11e4-9005-740ea37024e6.png)