Clock & Relative Times that Update Themselves

Implemented a clock that is available in the controller and model. This means it's also available in the views.

It's a very simple concept. Define a singleton object that has a `second`, `minute`, and `hour` attribute defined on it that updates based on the current time. Then you can use this clock to update other attributes by having them depend on the clock.

For example this property foo will update every second.
```coffeescript
foo:(->
  moment(new Date()).fromNow()
).property('clock.second')
```