Load advisory message in dashboard

- Current implementation uses a local file, publish it on orcharproject.net later

--HG--
branch : dev

src/Orchard.Web/Core/Dashboard/Controllers/HelperController.cs

@@ -0,0 +1,12 @@
+using System.Web.Mvc;
+using Orchard.Themes;
+
+namespace Orchard.Core.Dashboard.Controllers {
+    [Themed(false)]
+    public class HelperController : Controller {
+        
+        public ActionResult Index() {
+            return View();
+        }
+    }
+}