Clears remoteStream when user leaves.

JitsiConference.js

     }
     var participant = this.participants[id];
     delete this.participants[id];
+
+    this.rtc.removeRemoteStream(id);
+
     this.eventEmitter.emit(JitsiConferenceEvents.USER_LEFT, id, participant);
 };
 

modules/RTC/RTC.js

 function RTC(room, options) {
     this.room = room;
     this.localStreams = [];
-    //FIXME: we should start removing those streams.
     //FIXME: We should support multiple streams per jid.
     this.remoteStreams = {};
     this.localAudio = null;
     return remoteStream;
 };
 
+RTC.prototype.removeRemoteStream = function (resource) {
+    if(this.remoteStreams[resource]) {
+        delete this.remoteStreams[resource];
+    }
+};
+
 RTC.getPCConstraints = function () {
     return RTCUtils.pc_constraints;
 };