added a feedback modal form

var modal =
Alloy.createWidget("com.appcelerator.davidecassenti.modalwindow");
	var args={
		titleText : 'Feedback',
		message : 'Message',
		keyboardType : Ti.UI.KEYBOARD_DEFAULT,
		buttonText : 'Ok',
	};
	modal.feedback(args, function(e,returnText) {
	    Ti.API.info("User clicked OK");
	    Ti.API.info(returnText);
	});