Design active/selected item from grocery list.

[Russell Perkins]

When you select an item from the grocery list or the last item you submit should have an "active" class. When this class is active more options for the item should appear such as aisle and cost.

This issue is about creating that layout and applying it to all items in the grocery list. Bonus for wiring up the active class and hiding the rest.

Issue #10 should be completed before wiring up data binding.