Impossible to abort() XMLHttpRequest (because there is no way to refer to it)

This bug is really about that it's impossible to store certain kinds of objects as a QML property, but the particularly important consequence is that it's impossible to cancel the HTTP request from QML.

XMLHttpRequest supported by QML has an abort() method that works perfectly when you access it from where you create the object. For example the following works:

onClicked: {
            console.log("wholeArea clicked")
            var doc = new XMLHttpRequest();
            doc.onreadystatechange = function() {
                if(doc.readyState == XMLHttpRequest.DONE) {
                    console.log("conv: doc loaded fully: " + doc.responseText)

                } else if (doc.readyState == XMLHttpRequest.LOADING) {
                    console.debug("conv: doc readyState changed to LOADING")
                    doc.abort()
                } else {
                    console.debug("conv: doc readyState changed not to DONE or LOADING, but to " + doc.readyState);
                }
            }

            doc.open("GET", "http://az.lib.ru/t/tolstoj_lew_nikolaewich/text_0040.shtml");
            doc.send();
        }

Unfortunately you almost never would want to do that. You may want to cancel the loading from some completely different place e.g. when the user taps the "Cancel" button. And, surprisingly, there is no way to refer to XMLHttpRequest out of its original javascript scope. It is impossible to make a javascript object be a QML property and if you use variant, you can't call the abort function, you'll get "TypeError: Result of expression 'request.abort' [undefined] is not a function." See the example file attached