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/Accounting/AccountController.cs

@@ -27,6 +27,7 @@ using IdentityModel;
 using System.Security.Cryptography;
 using System.Text.Unicode;
 using System.Text;
+using Yavsc.Server.Helpers;
 
 namespace Yavsc.Controllers
 {