Update master branch to use a localStorage persistence service

[leggetter]

At the moment the Items blade persists the data. This is naughty! Persistence should be performed via a service.

We should consider whether this service listens to/triggers events. Or whether the blades directly access it and it has specific Todo List domain methods.

The benefit of sticking with the EventHub solution is that it keeps the BRJS presentation simple (you don't need to show how to create and register a service).

The problems with this are that 'fire and forget' style messaging can lead to problems e.g. how does the persistence service know when to trigger the initial load of todo-added events? How does it know when the listening blades are ready?