Shows the use of a custom controller, a value transformer, and two custom 
bindings-enabled views. One view is a control that allows you to set the angle 
and offset of a shadow; the other view observes and displays a collection of 
graphic objects.

Originally from `Cocoa Bindings Examples and Hints`__, converted to PyObjC 
by u.fiedler.

.. __: http://homepage.mac.com/mmalc/CocoaExamples/controllers.html