Added member type controller and resource, started getting creating members dialog working.

src/Umbraco.Web/UrlHelperExtensions.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Linq;
+using System.Linq.Expressions;
 using System.Web.Mvc;
 using Umbraco.Core;
 using Umbraco.Web.Mvc;
@@ -50,6 +51,13 @@ namespace Umbraco.Web
             return url.GetUmbracoApiService<T>(actionName).TrimEnd(actionName);
         }
 
+        public static string GetUmbracoApiServiceBaseUrl<T>(this UrlHelper url, Expression<Func<T, object>> methodSelector)
+            where T : UmbracoApiController
+        {
+            var method = Umbraco.Core.ExpressionHelper.GetMethodInfo(methodSelector);
+            return url.GetUmbracoApiService<T>(method.Name).TrimEnd(method.Name);
+        }
+
         /// <summary>
         /// Return the Url for a Web Api service
         /// </summary>