[cookbook] Continuous redrawing of views recipe

Recipe uses a clock object which is given to the controller via the an application initializer. The controller binds to the `pulse` property of the clock instance. The clock's `pulse` observes a property that is changed during an interval created with `Ember.run.later`. The controller also computes a `seconds` property to display the `pulse` value and creates flags used to render one of three components for an animated display. The result is the nyan cat animation (via components) and the display of seconds formatted using a helper, "You've nyaned for `clock`".

See: http://jsbin.com/iLETUTI/9/