Added a method to container that allows for removing items dynamically

Change-Id: Ibcc5eee453a65943a80141ada4cebe0aed0112f6
diff --git a/dev/demo/containermenudemo.js b/dev/demo/containermenudemo.js
index 9c81bf0..e3b0f99 100644
--- a/dev/demo/containermenudemo.js
+++ b/dev/demo/containermenudemo.js
@@ -92,9 +92,15 @@
   var ExampleItemList = new Array;
   ExampleItemList.push(OwnContainerItemClass.create());
   ExampleItemList.push(OwnContainerItemClass.create());
+  ExampleItemList.push(OwnContainerItemClass.create());
   ExampleItemList[0].value = "Example Item 1";
   ExampleItemList[0]._i = 3;
   ExampleItemList[1]._i = 4;
+  ExampleItemList[2].value = "Remove the Prefix Test";
+  ExampleItemList[2]._i=5;
+  ExampleItemList[2].onclick = function (e) {
+    this._menu.container().removeItemByIndex(3);
+  };
 
   //Own container class.
   var OwnContainerClass = {