Better JitsiTrack#dispose() method to prevent memory leaks

modules/RTC/JitsiLocalTrack.js

     this.resolution = resolution;
     this.deviceId = deviceId;
     this.startMuted = false;
-    this.disposed = false;
     this.initialMSID = this.getMSID();
     this.inMuteOrUnmuteProgress = false;
 
                     }
 
                     if(!streamInfo) {
+                        // FIXME: introduce new JitsiTrackError for that
                         reject(new Error('track.no_stream_found'));
                         return;
                     }
 /**
  * Stops sending the media track. And removes it from the HTML.
  * NOTE: Works for local tracks only.
+ *
+ * @extends JitsiTrack#dispose
  * @returns {Promise}
  */
 JitsiLocalTrack.prototype.dispose = function () {
+    var self = this;
     var promise = Promise.resolve();
 
     if (this.conference){
         this.detach();
     }
 
-    this.disposed = true;
-
     RTCUtils.removeListener(RTCEvents.DEVICE_LIST_CHANGED,
         this._onDeviceListChanged);
 
             this._onAudioOutputDeviceChanged);
     }
 
-    return promise;
+    return promise
+        .then(function() {
+            return JitsiTrack.prototype.dispose.call(self);
+        });
 };
 
 /**

modules/RTC/JitsiRemoteTrack.js

     this.eventEmitter.emit(JitsiTrackEvents.TRACK_VIDEOTYPE_CHANGED, type);
 };
 
-delete JitsiRemoteTrack.prototype.dispose;
-
 module.exports = JitsiRemoteTrack;

modules/RTC/JitsiTrack.js

     this.track = track;
     this.videoType = videoType;
 
+    this.disposed = false;
+
     if(stream) {
         if (RTCBrowserType.isFirefox()) {
             implementOnEndedHandling(this);
 };
 
 /**
- * Dispose sending the media track. And removes it from the HTML.
- * NOTE: Works for local tracks only.
+ * Removes attached event listeners.
+ *
+ * @returns {Promise}
  */
 JitsiTrack.prototype.dispose = function () {
+    this.eventEmitter.removeAllListeners();
+
+    this.disposed = true;
+
+    return Promise.resolve();
 };
 
 /**

modules/RTC/RTCUtils.js

             mediaStream.stop();
         }
 
+        // MediaStream in react-native-webrtc implementation has special
+        // "release" method to do the clean up of memory. We use it to prevent
+        // memory leaks.
+        if (mediaStream.release) {
+            mediaStream.release();
+        }
+
         // if we have done createObjectURL, lets clean it
         var url = mediaStream.jitsiObjectURL;
         if (url) {