ALPS document describing DISCO services
---------------------------------------
Allows services to register/unreg themselves in a shared, searchable registry of available services.
Allows services (including the registry) to perform a "ping" health-check
Allows services to "find/bind" to other services based on profile and mediaType criteria
returns a single registered item
register a service in the shared registry
unregister a service in the shared registry
sends a renewal request *from* a running service to the registry
send a health-check ping *to* a running service
ask for a filtered list of registered services that match the supplied criteria
assert a claim to using a service (sent to the registry)