A HeaderMapper implementation for mapping to and from a SoapHeader.
The inboundHeaderNames and outboundHeaderNames may be configured.
They accept exact name Strings or simple patterns (e.g. "start*", "*end", or "*").
By default all inbound headers will be accepted, but any outbound header that should
be mapped must be configured explicitly. Note that the outbound mapping only writes
String header values into attributes on the SoapHeader. For anything more advanced,
one should implement the HeaderMapper interface directly.