Cleaning up websecurity and implementing it, migrates security stamp and session id validation for cookie auth

src/Umbraco.Web/UmbracoInjectedModule.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Web;
 using System.Web.Routing;
 using Umbraco.Core;
+using Umbraco.Core.Security;
 using Umbraco.Core.Cache;
 using Umbraco.Core.Configuration;
 using Umbraco.Core.Exceptions;