Merge pull request #115 from legastero/fix-jingle-inheritance

Correctly subclass JingleSession

modules/xmpp/JingleSessionPC.js

     // stable and the ice connection state is connected.
     this.modifySourcesQueue.pause();
 }
-//XXX this is badly broken...
-JingleSessionPC.prototype = JingleSession.prototype;
+
+JingleSessionPC.prototype = Object.create(JingleSession.prototype);
 JingleSessionPC.prototype.constructor = JingleSessionPC;