edx/edx-platform — pull request #4260 by asadiqbal08 (2014-07-01 08:41:24+00:00)
Title: shopping cart coupon checkout changes as suggested by Jason Bau

@cdodge This PR contains the following change set :

Moved the model "CourseRegistrationCode" from student to shoppingcart app.
Rename the model "Coupons" to "Coupon".
Added the "price_list" field in orderitem model. (in order to build the track of orignal price)
Updated the migration files.
Remove the logic related to discount price and updating the unit_cost of an item.
Update the query in "get_total_amount_of_purchased_item" class method.
Replace the variable purchased_cart_items to cart_items
Updated the list and receipt templates ( referencing to unit_cost rather then discount_price)
logging the coupon code during removal of coupon redemption.
updated the test cases of shopping cart.