Kepler

Currently EcoGrid access in Kepler works but the EcoGrid node that is queried is
a single configurable parameter. This needs to be changed to dynamically access
the EcoGrid registry and get the list of nodes to be queried from the registry.
Then the kepler ecogrid query would be launched against these nodes, possibly
with the ability for the user to configure which nodes to search.

When searching multiple nodes, the results from each node need to be integrated.
The code for integrating the resultsets needs to accomodate different namespaces
(e.g., EML and Darwin Core) in the result set. The EcoGrid web interface will
also need this capability, so we can hopefully use the same resultset
integration code in both applications.

The current registry provides minimal metadata about each node, but eventually
we expect to have rich metadata (such as supported query namespaces, load,
coverage, etc). Once this metadata is available, the kepler client can be
smarter about which nodes are searched, possibly suggesting an appropriate
subset of nodes from the list.