Abstracted common GestureType hostLayer management
Implemented pan gesture handler
Changed tap recognizer to call handler with global location
Implemented touchedDescendents
Implemented currentVelocityInLayer
Example dragging layer around, convenience operators
Hit test to presentation layer
Bootstrapped dynamic animator API
Added point support to dynamic animator
Added lots more animatable properties
Animators can consume a POPAnimatableProperty
Added animator velocity