Add additional test for cloning of Elements.

Tests/Controller/SettingsTest.cs

@@ -49,6 +49,11 @@ namespace Tests.Controller
                 ((Items)source.Elements[1]).Content,
                 ((Items)clone.Elements[1]).Content,
                 "Items content");
+            ((Items)clone.Elements[1]).Content = "something else";
+            Assert.AreNotEqual(
+                ((Items)source.Elements[1]).Content,
+                ((Items)clone.Elements[1]).Content,
+                "Items content should be different");
         }
     }
 }