basic controller setup for incentive store
raw model for store carts
StoreCart.start(shopper, handler) for starting a new cart.
StoreCart#finish to wrap up a shopping session
A StoreCart belongs to its Client shopper.
StoreCart#handled_by relation; store controller can start a cart
oh yeah - /store/show
permissions for StoreCart; long-threatened fiddling with PointsEntryType navigation
adjust welcome tests; start shopping and display list of carts
showing and finishing a cart works
tests back in sync with reality.