Fix wrong inheritance method

"Child.prototype = new Parent()" should not be used. It has
problem. See the below test script.

"Child.prototype = Object.create(Parent.prototype)" should be used.

    var EventEmitter = require('events').EventEmitter;

    function Receiver() {
    };

    Receiver.prototype = new EventEmitter();

    Receiver.prototype.emitEvent = function() {
        this.emit("event");
    }

    receiver1 = new Receiver();
    receiver1.on("event", function() {console.log("receiver1")});
    receiver2 = new Receiver();
    receiver2.on("event", function() {console.log("receiver2")});

    receiver2.emitEvent();
    // -> receiver1
    // -> receiver2
    // receiver1 is also received the event that is emitted to receiver2.