Bleakwind Buffet Milestone 6
Added options for combo meals and implementation for an order. Fully functioning order summary that shows each item in the order, its price, and special instructions. Included is the ability to remove an item from the order upon selection and a summary of the current order's subtotal, tax, and total costs.
Updated UML to reflect implementation of INotifyPropertyChanged interface, ObservableCollection base class, Order class, and ComboMeal classes.
Also wrote additional tests for the Order and ComboMeal classes.