Send XML declarations with WSDL

When testing JBoss SOA-P for WS-I compliance, we found an interesting bug. Contrary to what XML says, the WS-I Test Tools consider the WSDL to be in UTF-8 if and only if it has an XML declaration that states so.

This technically isn't an issue on our part, as the WSDL clearly is UTF-8 and is well-formed, but the only way the WS-I Test Tools will ever know is when we actually include the XML declaration at the beginning of WSDL document. So this is a feature request asking for just that.

Specifying the content type in a HTTP header doesn't work as WS-I Test Tools only look at the declaration (and the lack thereof).