Cookbook/objects/continuous redrawing, removed unused code

Updated to the `Cookbook: Continuous Redrawing of Views` section, 
guides/cookbook/working_with_objects/continuous_redrawing_of_views

- Use the same jsbin version in the embedded and link to source code
- The section for "Binding to the `pulse` attribute" needed updates
  - Code in the example didn't match the jsbin
  - Removed code from example that wasn't actually used.