Bug 971543 - [System2] Make Rocketbar instantiable

https://bugzilla.mozilla.org/show_bug.cgi?id=971543

![screen shot 2014-04-30 at 2 40 29 pm](https://cloud.githubusercontent.com/assets/122602/2847583/182481cc-d0b0-11e3-9537-0c8205aa8463.png)