Revisit statuses of Request/RequestItem

[GPKyte]

Currently
public enum RequestStatus {ORDERED, IN_PROCESS, COMPLETE, NOTIFIED, DELIVERED}

Should reflect the full life-cycle of the request. Note that RequestItemStatus (DNE) is a subset of containing only the first three elements. We will move into the NOTIFIED/DELIVERED statuses only when all RequestItems are COMPLETE and the requester have been emailed and have picked up their print.

We can also consider adding CANCELED for special cases.