Cart churn as code and POD is re-ordered in prep for rehack
remove get/set_name accessors
remove get/set_sessions_id from Cart
remove use of CONSTANT for default cart name in Cart
remove Cart set/get_users_id
remove created and last_modified which add no value
remove get_products access from Cart
some pod cleanup + replacement of some loops with map
smal changes + perltidy of Cart
add discount_percent to Cart
rename cart_products_id in Cart::Product to id
add discount code to Cart::Product
lots of new cost tests
small Types change