OSID - osid.OsidReceiver Service Interface Definition

Interface	osid.OsidReceiver
Description	An `OsidReceiver` is used to receive asynchronous notifications from a service. The receiver defines the interface to be implemented by the consumer.
Method	up
Description	The callback for notifications that the notification bus is operational.
Compliance	`mandatory`	This method must be implemented.
Method	down
Description	The callback for notifications that the notification bus is not operating.
Compliance	`mandatory`	This method must be implemented.