Make Boo fade away when he's trying to hide
Change start of AVCaptureSession

It looks broken if the session is already in place while he's fading into view on application launch, so I moved it into the completion block of the animation.
Merge branch 'master' of https://github.com/Erikmitk/Peek-A-Boo

Something is still not right in this setup. I should probably checkout fresh and directly from Github.