Investigate a solution for handling silent changes to Backbone Collections

[EvHaus]

Consider this scenario:

var collection = new Backbone.Collection();
new DobyGrid({data: collection});

// Silently add an item to the collection so that DobyGrid doesn't know about it
collection.add({id: 123}, {silent: true})

// Try to edit the row
collection.get(123).set({name: 'test'});

// DobyGrid will fail in the setItem() method trying to find that item

Not sure what we should do here. Keep the error? Show a warning instead? Simply do nothing silently?

[EvHaus]

Duplicate of #49