taneously.
 *
 * This may be used to capture DOM events:
 *
 *     Element.keyDownEvent.forTarget(element, useCapture: true).listen(...);
 *
 *     // Alternate method:
 *     Element.keyDownEvent.forTarget(element).capture(...);
 *
 * Or for listening to an event which will bubble through the DOM tree:
 *
 *     MediaElement.pauseEvent.forTarget(document.body).listen(...);
 *
 * See also:
 *
 * [addEventListener](http://docs.webplatform.org/wiki/dom/methods/addEventListener)
 */
Stream&lt;T&gt; forTarget(E