fix EventTarget.prototype inheritance and dispatchEvent update on stream on removeTrack and addTrack

Author: hthetiot

js/EventTarget.js

@@ -11,6 +11,8 @@ var EventTarget = function () {
 EventTarget.prototype = Object.create(YaetiEventTarget.prototype);
 EventTarget.prototype.constructor = EventTarget;
 
+Object.defineProperties(EventTarget.prototype, Object.getOwnPropertyDescriptors(YaetiEventTarget.prototype));
+
 EventTarget.prototype.dispatchEvent = function (event) {
 
 	Object.defineProperty(event, 'target', {

js/MediaStream.js

@@ -277,6 +277,8 @@ MediaStream.prototype.addTrack = function (track) {
 	addListenerForTrackEnded.call(this, track);
 
 	exec(null, null, 'iosrtcPlugin', 'MediaStream_addTrack', [this.id, track.id]);
+
+	this.dispatchEvent(new Event('update'));
 };
 
 
@@ -301,6 +303,8 @@ MediaStream.prototype.removeTrack = function (track) {
 
 	exec(null, null, 'iosrtcPlugin', 'MediaStream_removeTrack', [this.id, track.id]);
 
+	this.dispatchEvent(new Event('update'));
+
 	checkActive.call(this);
 };