Status class should have a Throwable field

[Paul J. Lucas]

I would like to be able to have code like:

        try {
            // ...
        }
        catch ( SomeException e ) {
            response.setStatus( CLIENT_ERROR_BAD_REQUEST, e );
        }
That is that you can pass a Throwable to setStatus() and that the  
Status class have the additional methods of:

        void setThrown( Throwable t );
        Throwable getThrown();

The default implementation of the response that gets returned to the  
client will simply do an:

        t.getMessage()

and include that as the textual error message.  However, if I  
implement my own StatusService, I have full access to the exception.   
In my case, I'd like to return an XML entity containing an XML-ized  
version of the exception's stack trace.

- Paul