BlurManager

* Hello guys, this is my BlurManager implemented as a system service + internal API.
The usage is very simple. At the moment you can retrieve a blurred wallpaper, a blurred screenshot of the running activity or blur your custom bitmap.
I'm also working in another api to blur custom views.

To get a blurred screenshot you have to call the prepare() void.

* An interface void will be called once the bitmap is ready returning the blurred bitmap.

You can check my other upcoming commit for blurring recents panel to understand how it works but im sure you'll get it easyli.

This is a little gift for Sean :)

Change-Id: I1b01a287f9b40520bd11f5c74810d98f3d2d1415
Recents goes blur

Change-Id: I66681bf5228c806ae6bb50832028f198825e3cf7