Add C# Razor completion for MVC helper methods.

Use WebViewPage<dynamic> as Razor view's base class.
Add default namespaces for the Razor view class so extension methods show in completion:
  System.Web.Mvc,
  System.Web.Mvc.Ajax,
  System.Web.Mvc.Html,
  System.Web.Routing

The Razor view's base class and namespaces should be taken from the web.config but are currently hard coded.

src/AddIns/BackendBindings/AspNet.Mvc/Project/Src/Completion/RazorCSharpDotCompletionDataProvider.cs

@@ -2,6 +2,7 @@
 // This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
 
 using System;
+using System.Collections.Generic;
 using ICSharpCode.SharpDevelop;
 using ICSharpCode.SharpDevelop.Dom;
 using ICSharpCode.SharpDevelop.Dom.NRefactoryResolver;
@@ -31,10 +32,32 @@ namespace ICSharpCode.AspNet.Mvc.Completion
 		ParseInformation CreateParseInformationWithWebViewPageClass(ParseInformation parseInfo)
 		{
 			var compilationUnit = new DefaultCompilationUnit(parseInfo.CompilationUnit.ProjectContent);
+			AddDefaultUsings(compilationUnit);
 			AddWebViewPageClass(compilationUnit);
 			return new ParseInformation(compilationUnit);
 		}
 		
+		void AddDefaultUsings(ICompilationUnit compilationUnit)
+		{
+			AddUsing("System.Web.Mvc", compilationUnit);
+			AddUsing("System.Web.Mvc.Ajax", compilationUnit);
+			AddUsing("System.Web.Mvc.Html", compilationUnit);
+			AddUsing("System.Web.Routing", compilationUnit);
+		}
+		
+		void AddUsing(string name, ICompilationUnit compilationUnit)
+		{
+			DefaultUsing defaultUsing = CreateUsing(name, compilationUnit.ProjectContent);
+			compilationUnit.UsingScope.Usings.Add(defaultUsing);
+		}
+		
+		DefaultUsing CreateUsing(string namespaceName, IProjectContent projectContent)
+		{
+			var defaultUsing = new DefaultUsing(projectContent);
+			defaultUsing.Usings.Add(namespaceName);
+			return defaultUsing;
+		}
+		
 		void AddWebViewPageClass(DefaultCompilationUnit compilationUnit)
 		{
 			DefaultClass webViewPageClass = CreateWebViewPageClass(compilationUnit);
@@ -52,12 +75,20 @@ namespace ICSharpCode.AspNet.Mvc.Completion
 		
 		void AddWebViewPageBaseClass(DefaultClass webViewPageClass)
 		{
-			IClass webViewPageBaseClass = webViewPageClass.ProjectContent.GetClass("System.Web.Mvc.WebViewPage", 0);
+			IClass webViewPageBaseClass = webViewPageClass.ProjectContent.GetClass("System.Web.Mvc.WebViewPage", 1);
 			if (webViewPageBaseClass != null) {
-				webViewPageClass.BaseTypes.Add(webViewPageBaseClass.DefaultReturnType);
+				IReturnType returnType = GetWebViewPageBaseClassReturnType(webViewPageBaseClass);
+				webViewPageClass.BaseTypes.Add(returnType);
 			}
 		}
 		
+		IReturnType GetWebViewPageBaseClassReturnType(IClass webViewPageBaseClass)
+		{
+			var typeArguments = new List<IReturnType>();
+			typeArguments.Add(new DynamicReturnType(webViewPageBaseClass.ProjectContent));
+			return new ConstructedReturnType(webViewPageBaseClass.DefaultReturnType, typeArguments);
+		}
+		
 		DomRegion GetRegionInMiddleOfWebViewPageClass()
 		{
 			return new DomRegion(2, 0, 2, 0);