Remove terrible display:none Marionette hack

examples/backbone_marionette/css/app.css

@@ -2,9 +2,3 @@
 #todoapp.filter-completed #todo-list .active {
 	display: none;
 }
-
-#main,
-#footer {
-	display: none;
-}
-

examples/backbone_marionette/js/TodoMVC.TodoList.js

@@ -27,9 +27,14 @@ TodoMVC.module('TodoList', function (TodoList, App, Backbone, Marionette) {
 			this.showHeader(this.todoList);
 			this.showFooter(this.todoList);
 			this.showTodoList(this.todoList);
+			this.todoList.on('all', this.updateHiddenElements, this);
 			this.todoList.fetch();
 		},
 
+		updateHiddenElements: function () {
+			$('#main, #footer').toggle(!!this.todoList.length);
+		},
+
 		showHeader: function (todoList) {
 			var header = new App.Layout.Header({
 				collection: todoList