Trigger: passing extra arguments in the fireEvent case.

[charles-dexter-ward]

If browser does not support createEvent(), realTrigger() tries to use fireEvent() without merging any extra argument which are passed to it. This is a problem in IE 7 and IE8 because no extra information could be merged with the event object.

realTrigger() could be modified as the following, when fireEvent() has to be invoked:

if (document.createEventObject && a) { 
    var evt = document.createEventObject (window.event);
    a && mix(evt, a);
    n.fireEvent(ev, evt);
} else {
    n.fireEvent(ev);
}