Make the update function in session module an async construct that waits until the state of the game has been updated

src/session.js

@@ -1,4 +1,4 @@
-function Session() {
+function Session(async) {
 	var game = JSON.parse(localStorage.getItem('game'));
 	var options = JSON.parse(localStorage.getItem('options')) || defaultOptions();
 
@@ -6,15 +6,24 @@ function Session() {
 		getOptions: getOptions,
 		getGame: getGame,
 		save: save,
-		setOptions: setOptions
+		setOptions: setOptions,
+		update: update
 	};
 
 	function getGame() {
 		return game;
 	}
 
-	function update(state) {
-		game = state;
+	function update() {
+		return async.bind(
+			messaging.receive(function(message) {
+				return message.tag == "Game";
+			}),
+			function(message) {
+				game = message.contents;
+				return async.wrap();
+			}
+		);
 	}
 
 	function save() {