Return a collection of items on GET, otherwise dump the JSON to the console
Items listen to change and destroy events.
We now pass 'when' around as an ISO date/time string (see also server.py) so update our template helper.
Add a 'refresh' button; remove #go selector from button styling
Refresh button triggers a model sync; parameterise AppView on an ItemCollection
Refactor AppView tests slightly; manipulate collection directly as well as using 'go' button
Tests for removing an item from the collection