Updated for Spree 1.2. 

Stripped of ability to add credits, as that was dependent on the Admin/Users interface that has been removed. That piece should be brought into User management of parent app anyways. If someone wants to build a new UI on top of it, be my guest. 

Decorating the Spree.user_class, and adjusted to work with new checkout flow state_machines in order.rb

Verified working with 1.2 w/ custom auth / checkout state machines