OpenSearch

We have a new draft of the OpenSearch binding
http://www.oasis-open.org/committees/download.php/41618/opensearch-march-25-2011.doc

(And my thanks to Tony, who did the necessary research to determine the changes in version 5, since draft 3 on which the previous version was based.)

Please review this, since it has been quite awhile since we revised it.

This needs a conformance clause. I'm not sure what to do about that. Do we want to model it after the SRU conformance? That would mean adding a whole bunch of formality (protocol model) which  I don't think we want to do that.  Someone want to draft up a simple conformance clause? The simpler the better.