wadl-client does not expose response headers

[christopherdcunha]

Currently, the callback in:

...
    client.item.post()
      .withHeaders(headers)
      .send(JSON.stringify(body))
      .onValue(callback);
...

will only receive the response body from the backend (

wadl-client/wadl-client.js

Lines 142 to 160 in 04c2de0

	xhr.onreadystatechange = function() {
	if(xhr.readyState == 4) {
	try {
	if(xhr.status >= 200 && xhr.status < 300) {
	Utils.send(sink, options.parse ? Utils.parseBody(xhr) : xhr.responseText);
	}
	else if(xhr.status === 0 || xhr.reason === "timeout") {
	Utils.logError(options.logger, xhr.responseText);
	Utils.send(sink, new B.Error({code: "ETIMEDOUT"}));
	}
	else {
	Utils.send(sink, new B.Error(options.parse ? Utils.parseBody(xhr) : xhr.responseText));
	}
	} catch(e) {
	Utils.logError(options.logger, "An error occured while parsing: " + xhr.responseText);
	Utils.send(sink, new B.Error(e));
	}
	}
	};

)

My use-case requires me to get the response headers. I can update the abovementioned code to return xhr object directly but this would not be backwards compatible. Any thoughts?