Introduce `persist_order_address` message for user

This would be resposible for associating the current order address with
the current user so that next time users checkout an order his previous
address would be automatically loaded
Add basic module for persisting order address on user

To make Spree remember user address on checkout users could include this
module to their Spree.user_class or build their own implementation of
`persist_order_address`
Allow users to choose whether they want to save their addresses