Get ecogrid endpoints from Ecogrid registry
Sibling bug to bug #2490 in kepler.
Currently, individual endpoints for SRB, metacat, GEON, and Digir ecogrid implementations are stored in a config file for the ecogrid portal. Unfortunately, these endpoint may change. Ecogrid needs to be updated to retreive these from the Ecogrid registry (daily? hourly?) so that they can change and just send new values to the registry.