New Extensions 9 (hope code everywhere correct)

- Added totalPrice in prescription list using cur.totalPrice:
@Override
public Prescription createPrescription(long customerId, String issuer,
double totalPrice) {
Prescription newPrescription =
getCustomer(customerId).createPrescription();
newPrescription.setIssuer(issuer);
newPrescription.setTotalPrice(totalPrice);
em.persist(newPrescription);
return newPrescription;
}