Expedited exchanges

When a return authorization is saved
Given a return item has a requested exchange
Then an exchange shipment for the exchange items for the return authorization are generated immediately

Given an exchange shipment has been generated pre-return
Given a customer has not returned their item after X days
Then create a new order with the exchange shipment and capture payment for the full amount of the items

Conflicts:
	core/config/locales/en.yml

cherry-picked from f443bd190fc5f7517048febd3c54d38a749baa46 in spree master