added a few TODOs ...
completed clip "preemptive" start logic
Merge branch 'master' of https://github.com/jcbatista/KinectSilhouetteVideoOverlay into dev-prestart
Merge branch 'master' of https://github.com/jcbatista/KinectSilhouetteVideoOverlay into dev-transition
decoupled the timeline from the ActionClipManager