Initial commit.

Simple view that has a force applied.
Add gravity and a boundary to collide with
Setup a tabbed interface to swap between different demo view controllers.
Move DynamicButton to it's own file and stub in the angular controller.
Add a 3rd tab to experiment with collisions
Add a 4th tab that demos some attachment behaviors.

Allow dragging of a view via an attachment and pan gesture.
Attach two items with a non-rigid spring-like attachment.

Add a custom dynamic item that can be used to log dynamic item changes for debugging.

Make the force of the push behavior for buttons scale with the area of the view.
Merge branch 'master' of https://github.com/twenty3/Dynamics-Play