Instantiate an instance of the GoogleCheckout Polling prototype

Examples:

var gc = new GoogleCheckout({ merchantNumber : '1234', merchantKey : 'ABCD', currency : 'USD'});
var p = new Polling(gc);

This is not really necessary though because an instance of GoogleCheckout contains
an instance of Polling

var gc = new GoogleCheckout({ merchantNumber : '1234', merchantKey : 'ABCD', currency : 'USD'});

gc.Polling.on('newOrderNotification', function (order) {
console.log(order)
});

gc.Polling.run();

Continue Token Events:

- notificationDataTokenResponse - 'Raw'
- continueToken


Notification Events:

- notificationDataResponse - 'Raw'
- newOrderNotification
- authorizationAmountNotification
- riskInformationNotification
- orderStateChangeNotification
- chargeAmountNotification
- refundAmountNotification
- chargebackAmountNotification

@param {Object} objGoogleCheckout An instance of a GoogleCheckout object
@return {Object} Polling Object
@api public
function Polling (objGoogleCheckout) {
	var self = this;
	
	//todo: check the constructor name
	assert.ok(objGoogleCheckout, "A GoogleCheckout object is the only required argument");
	
	self.gc = objGoogleCheckout;
	self.settings = self.gc.settings;
	self.continueToken = null;
}