Carrier for FedEx

Initial release.
FedEx through the REST APIs (Rate, Ship, Track, Pickup, Locations and Address Validation), with sandbox and production environments.
OAuth client-credentials authentication, with the keys sent in the form body as FedEx requires. Tokens are cached for the hour FedEx grants and refreshed a minute early.
Live rates for one service or every service at once, with account rates (falling back to list), transit days and estimated delivery dates.
FedEx Ground and FedEx Home Delivery treated as one product: the right one is chosen for each address.
Labels as PDF 4×6, PDF on a US Letter sheet, ZPL or PNG.
Multi-package shipments of up to 40 packages, with one tracking number and label per package.
Print return labels, with the parties swapped.
International shipments, with customs commodities built from Carrier's customs lines and a choice of DDU or DDP.
Cancellation by master tracking number.
Tracking of up to 30 numbers per request, with full scan history mapped onto Carrier's statuses, delivery dates and who signed.
FedEx location search for the checkout picker, and Hold at Location delivery to the chosen one.
On-call pickups for FedEx Ground or FedEx Express.
Address validation with the corrected address and residential/business classification.
Signature, adult signature, Saturday delivery and residential delivery accessorials.

Version 5.0.0