Enabled switching back and forth between Home and Settings pages with the same button.
Added index of listview items.
Added ability to navigate to Settings from multiple pages and then go back to the same one (holding information about the previous view). Also added a view for task details. Changed the definition of listview item view, to focus on behavior of the application.
Refactored switch page message into a shared generic method which can be used by all control viewmodels.