Bug 946452 - Rocketbar Search App

What have we done?

* Added rocketbar preference in developer settings.
* When enabled, swiping down from the top left will open a global search bar.
* When enabled, tapping on the homescreen search bar will trigger the rocketbar to open.
* The utility try will open when the preference is turned off, or if you swipe down from the top right when it's enabled.
* The search bar searches: Contacts, Installed Apps, and E.me results.
* The search results app is a standalone app, and we can add functionality in the future to have replaceable search apps if we wish.
* Entering URLs in the search bar will launch a browser chrome.
* Everything.me results are displayed under the local results. Tapping on them will launch them.