Created abstract class Item.  Changed FoodItem to extend Item.  Added test cases to FoodItemTest.  Removed RepeatNumber and RepeatNumberTest.
Created abstract class Item. Wrote and tested FoodItem and ListItem.
Refined ListOfItems interface.  Created ShoppingList to implement ListOfItems.  Created ShoppingListTest to test ShoppingList.
Refined ListOfItems.
Added instructions for instantiating a ListItem.
Made minor coding improvements per Marks's comments.  Added equals() and hashCode() to ShoppingList.  Also added itemExistByName(String name) to check if an item already exists by a specified name.
Removed Collections import from ShoppingList.java.  It was left there by mistake.
Merge pull request #5 from niffer01/master

Coded FoodItem, ListItem, and ShoppingList.