Update #17 - Made cosmetic changes to Customer, DiscountStrategy, FlateRateDiscount, LineItem, QuantityDiscount, Receipt, and NoDiscount.  Also added validation to the NoDiscount class.
Update #18 - Commented out the Main method in NoDiscount.  Added validation to the methods with parameters in the FlatRateDiscount class.
Update #19 - Fixed setDiscountRate method validation in FlatRateDiscount.  Added validation to the methods with paramters within the QuantityDiscount class.
Update #20 - Added javadoc class comment in FlatRateDiscount class.  Added Date information to Receipt class.
Update #20 - Added javadoc method comments to FlatRateDiscount class.
Update #21 - Added javadoc method comments to NoDiscount class.
Update #22 - Added javadoc method comments to QuantityDiscount class.  Updaed FlatRateDiscount & NoDiscount classes javadoc comments to include the @param where needed.
Update #22 - Added javadoc method comments to QuantityDiscount class.  Updaed FlatRateDiscount & NoDiscount classes javadoc comments to include the @param where needed.
Update #23 - Added javadoc method comments to DiscountStrategy class.
Update #24 - Added javadoc class & method comments and method validation to Product class.
Update #25 - Begun adding javadoc class & method comments and method validation to LineItem class.  Made cosmetic changes to remove all unnecessary comments from QuantityDiscount, NoDiscount, FlatRateDiscount classes.
Update #26 - Made cosmetic changes to remove all unnecessary comments from Product class.
Update #27 - Finalized the class & method javadoc comments for the Lineitem class.  Made some additional cosmetic changes to the Product, DiscountStrategy, FlatRateDiscount, NoDiscount, QuantityDiscount classes.
Update #28 - Changed product numbers, descriptions, and unit cost within the FakeDatabase class for the products.  Changed the Startup class to show updated product numbers.  Modified LineItem getLineItem method for clearer printing on receipt.  Modified Receipt generateReceipt method for clearer printing on the receipt.
Update #29 - Added a generateReceiptHeader() & generateReceiptFooter() method to the Receipt class.
Update #30 - Modified validation for setQuantity method, and changed the getLineItem method so that I cold perform decimal formatting on the double amounts within the LineItem class.
Update #31 - Added javadoc class and method comments to CashRegister class, along with adding validation to the applicable methods.
Update #32 - Fixed validation for CustomerId in CashRegister class.  Added validation within the Customer class.
Update #33 - Added javadoc comment for the class and methods within the Customer class.
Update #34 - Modified the getCustomer method validation within the Receipt class.