add relationship section to service metadata

[elmex]

dpws 2006:

592 wsdp:Relationship/wsdp:Hosted
593 Endpoint References for a HOSTED SERVICE. If omitted, implied value is the
594 Endpoint Reference of the SERVICE that returned this metadata in a Get
595 Response SOAP ENVELOPE. At least one of ./wsdp:Host or ./wsdp:Hosted MUST
596 be included.
597 For the hosting relationship type, if a host has more than one HOSTED SERVICE,
598 including one relationship that lists all HOSTED SERVICEs is equivalent to
599 including multiple relationships that each list some subset of the HOSTED
600 SERVICEs.

dpws 2009:

575 dpws:Relationship/dpws:Hosted
576 This is a section describing a HOSTED SERVICE. . It MUST be included by a DEVICE for each
577 of its HOSTED SERVICEs. It MUST be included by a HOSTED SERVICE for itself. For the
578 hosting relationship type, if a host has more than one HOSTED SERVICE, including one
579 relationship that lists all HOSTED SERVICEs is equivalent to including multiple relationships that
580 each list some subset of the HOSTED SERVICEs.

619 R5020: A HOSTED SERVICE MUST have one Metadata Section with http://docs.oasis-open.org/ws-
620 dd/ns/dpws/2009/01/Relationship".

As specified in the specs a metadata response to a service should also include a relationship section with the corresponding hosted element.