padded add URL dropdown-menu

Before:
![before](https://f.cloud.github.com/assets/1847157/368946/d53a0e16-a2cc-11e2-9219-715e6c7705b6.png)

After:
![after](https://f.cloud.github.com/assets/1847157/368947/d53e5dc2-a2cc-11e2-80f8-5d0f10ef79bf.png)