[TIMOB-13649] DashboardView fires delete events for all items even when not in edit mode

According to the [documentation](http://docs.appcelerator.com/titanium/latest/#!/api/Titanium.UI.DashboardView-event-delete), the delete event for DashboardView is {quote} Fired when an item is deleted in edit mode. {quote} However, a delete event will be fired for every item in a dashboardview even when not in edit mode. If you, for example, called setData() programmatically to reset the DashboardView, an individual delete event is fired for all items that are going to be replaced, which probably doesn't make sense in the context of a wholesale replace. It is also pretty noisy. In addition, setData() is used by Alloy data binding to reset the dashboard when the model is updated.