Implicit java-xml-typemapping sourced from <service-endpoint-method-mapping>

The processing of the jaxrpc mapping file currently uses the <java-xml-type-mapping> elements to define a mapping between java and XML types.

It seems that the <service-endpoint-method-mapping> elements also define such mappings. Indeed, <method-param-parts-mapping> and <wsdl-return-value-mapping> define a mapping between java types and messape parts (hence XML types).

The implementation needs to be improved to use the <service-endpoint-method-mapping> elements.