Fix cache key for PricingCacheHandler.get_product_price_range
Merge pull request #79 from bartels/pricing-cache-fixes

Fix cache key for PricingCacheHandler.get_product_price_range
Cosmetics
two small fixes
Merge pull request #80 from antoninb/master

two small fixes
fix missing comma in order_list_templates
Merge pull request #81 from antoninb/master

Fix missing comma in order_list_templates
Variant form class as provider attribute in simplepost app
Checkout additional tests (related to previous commit fixes)
Use cart api in cart app/handler
Remove unusable context processor from cart app
Replace full_name with first_name/last_name in contact model
Contact app tests fixes
Refactored OrderedItems to allow for subclassing.
Refactored quantity validation to allow additional params to be passed to add_item call
Merge pull request #82 from dsldsl/master

OrderedItem Subclassing
make models abstract so that checkout works with custom models
make it easy to override billing_form class in multistep checkout app
add a per-country delivery option provider
mostly working refactored checkout where shipping address belongs to
DeliveryGroup instead of being a DeliveryVariant and dependent on having
chosen delivery_type.
make Mamona backend work nicely with the abstract order models and
multistep checkout