Do not call refresh_shipment_rates on an order if it is complete

Fixes #3648
Added missing internationalization for table headers (using same table headers as in shared/_order_details)

Fixes #3656
Use jquery.payment for frontend + backend checkout form
No longer create duplicate roles within Spree

Fixes #3557
[backend] use 'complete?' not 'completed?' in orders_controller_spec
Fix issue where refresh_rates for a shipment wasn't being called in VERY specific circumstances

The order_details_spec in backend was failing because of the absence of this code.
Update columns using update_column, rather than update_attribute which now calls callbacks.

Calling the callbacks causes the shipments to be reset to pending because, for some reason I did not investigate, the inventory units are set to 'backordered'. Do not want.
[backend] Correct orders_controller_spec stubbing
Fill in card expiry in checkout_spec
Allow 'expiry' to be passed through as a source attribute
[frontend] Fix translation for 'Expiration' in checkout/payment/_gateway