[Example] Add composite services example

Add an example showing the use of composite services,
WTD-518.

example/composite/src/SomeAggregator.js

@@ -0,0 +1,29 @@
+/*global define,Promise*/
+
+/**
+ * Module defining SomeAggregator. Created by vwoeltje on 11/5/14.
+ */
+define(
+    [],
+    function () {
+        "use strict";
+
+        /**
+         *
+         * @constructor
+         */
+        function SomeAggregator(someProviders) {
+            return {
+                getMessages: function () {
+                    return someProviders.map(function (provider) {
+                        return provider.getMessages();
+                    }).reduce(function (a, b) {
+                        return a.concat(b);
+                    }, []);
+                }
+            };
+        }
+
+        return SomeAggregator;
+    }
+);