Create Asset ID resolver

[dpsnowden]

The registry + catalog now have all the pieces in place to build an observing asset urn resolver -- something we've talked about in the past. What's most interesting is that you have the opportunity for listing all services that provide data for a particular asset urn, and specifically for an asset urn with a WMO ID, parsing the SOS GetCapabilities and DescribeSensor/WMO ID (assuming the data provider is providing the WMO ID in a compliant way).

So, something like this:
http://catalog.ioos.us/resolver/asset/urn:ioos:station:wmo:46123
Would return a link to NANOOS asset urn:ioos:station:nanoos:orca_twanoh
http://catalog.ioos.us/datasets/542fa18d8c0db36ba3043d69
and potentially a similar link to the dataset (asset) on the NDBC SOS.

That would be very cool and helpful. Even better if it also had a machine friendly response (JSON) that returned, say, the SOS DescribeSensor URL for the asset, for each matching SOS service.