Add complexity to the example app

* Added stupid page routing and a navigation component as an example until we have Routr ready
* Added a second store called TimeStore for a Timestamp sub-component
  * shows async handling
  * does polling (setInterval as an example)
  * handles a second event when clicking on the timestamp
  * emits update events when the time has changed

While I was implementing this, I'm starting to feel like the `final` emit may not be the best way to go and maybe we should switch to a callback interface for dispatch handlers (but still emitting `update` events for state change notification).