TRUNK-4565 - Null Pointer Exception for some DrugOrders

TRUNK-4565 - andreweskeclarke - NullPointer can still happen if the DB row has a null value, replace mixed up booleans

TRUNK-4565 - andreweskeclarke - Use appropriate clone for discontinue test

TRUNK-4565 - andreweskeclarke - When comparing DrugOrder drugs during dicontinuations, check if both should be null, otherwise check both for equality