Got .Field method for MVC working and have macro's rendering inside of RTE in MVC.

Added internal setting for global settings to return an MVC area string based on the umbraco path.
Added a ton of extension methods from v5 that are used in much of the MVC engines.
Added UmbracoHelper methods for MVC rendering including Field so that we can render the correct RTE
field markup when the RTE contains a macro, will add extension methods for the @CurrentPage dynamic object to
do the same to make it consistent.

src/Umbraco.Web/ModelStateExtensions.cs

@@ -0,0 +1,76 @@
+using System.Linq;
+using System.Web.Mvc;
+
+namespace Umbraco.Web
+{
+	internal static class ModelStateExtensions
+	{
+
+		/// <summary>
+		/// Merges ModelState that has names matching the prefix
+		/// </summary>
+		/// <param name="state"></param>
+		/// <param name="dictionary"></param>
+		/// <param name="prefix"></param>
+		public static void Merge(this ModelStateDictionary state, ModelStateDictionary dictionary, string prefix)
+		{
+			if (dictionary == null)
+				return;
+			foreach (var keyValuePair in dictionary.Where(keyValuePair => keyValuePair.Key.StartsWith(prefix + ".")))
+			{
+				state[keyValuePair.Key] = keyValuePair.Value;
+			}
+		}
+
+		/// <summary>
+		/// Checks if there are any model errors on any fields containing the prefix
+		/// </summary>
+		/// <param name="state"></param>
+		/// <param name="prefix"></param>
+		/// <returns></returns>
+		public static bool IsValid(this ModelStateDictionary state, string prefix)
+		{
+			return state.Where(v => v.Key.StartsWith(prefix + ".")).All(v => !v.Value.Errors.Any());
+		}
+
+
+		//NOTE: we used this alot in v5 when we had editors in MVC, this was really handy for knockout editors using JS
+
+		///// <summary>
+		///// Adds an error to the model state that has to do with data validation, this is generally used for JSON responses
+		///// </summary>
+		///// <param name="state"></param>
+		///// <param name="errorMessage"></param>
+		//public static void AddDataValidationError(this ModelStateDictionary state, string errorMessage)
+		//{
+		//    state.AddModelError("DataValidation", errorMessage);
+		//}
+
+		/// <summary>
+		/// Serializes the ModelState to JSON for JavaScript to interrogate the errors
+		/// </summary>
+		/// <param name="state"></param>
+		/// <returns></returns>
+		public static JsonResult ToJsonErrors(this ModelStateDictionary state)
+		{
+			return new JsonResult
+				{
+					Data = new
+						{
+							success = state.IsValid.ToString().ToLower(),
+							failureType = "ValidationError",
+							validationErrors = from e in state
+							                   where e.Value.Errors.Count > 0
+							                   select new
+							                   	{
+							                   		name = e.Key,
+							                   		errors = e.Value.Errors.Select(x => x.ErrorMessage)
+							                   	.Concat(
+							                   		e.Value.Errors.Where(x => x.Exception != null).Select(x => x.Exception.Message))
+							                   	}
+						}
+				};
+		}
+
+	}
+}