Added Manage button to Notifications screen

Fixes #1167 

Added a "Manage" button to the top of the Notifications window to get right to the settings for push notifications.

![img_0001](https://f.cloud.github.com/assets/373903/2224720/683de590-9a82-11e3-971c-bd0ca5db4d82.PNG)

![img_0042](https://f.cloud.github.com/assets/373903/2224734/8a1697fc-9a82-11e3-9f27-c48a9853c339.PNG)