Provide a default page for the RESTServlet to use if the '?query' parameter is not specified. Right now it just reports an "API" error ("query" not specified). It should be something a bit nicer than that. We can probably just use a static page for the moment, or you can do a FORM for submitting queries by hand, documentation on what the user can do, etc. This might eventually evolve into a "console" for the NSS, but we can start simple.