UI: use larger icon for edited advanced area to match the button size

Before:
![before](https://cloud.githubusercontent.com/assets/206841/3712293/691dc5c2-150a-11e4-9c38-82a5f89d9d04.png)
After:
![after](https://cloud.githubusercontent.com/assets/206841/3712294/691e17c0-150a-11e4-87ee-f7f418a97038.png)