* Option 2: HTTP response-headers that include an X-XRDS-Location response-header, together with a
* document (NOTE: we can probably recurse for this)
*
* Option 3:. HTTP response-headers only, which MAY include an X-XRDS-Location response-header,
* a contenttype response-header specifying MIME media type, application/xrds+xml, or both.
* Option 2: HTTP response-headers that include an X-XRDS-Location response-header, together with a
* document (NOTE: we can probably recurse for this)
*
* Option 3:. HTTP response-headers only, which MAY include an X-XRDS-Location response-header,
* a contenttype response-header specifying MIME media type, application/xrds+xml, or both.