Refactoring

The main server owns the migrations, it's the server part,
it's simpler.

It's Yavsc, not one of its lib.

src/Yavsc/Controllers/Contracting/ActivityController.cs

@@ -9,6 +9,7 @@ namespace Yavsc.Controllers
     using Models;
     using Models.Workflow;
     using Yavsc.Helpers;
+    using Yavsc.Server.Helpers;
 
     [Authorize("AdministratorOnly")]
     public class ActivityController : Controller