Add copyright notices to new files

src/Microsoft.AspNet.Mvc.Core/Rendering/ModelExpression.cs

@@ -1,4 +1,6 @@
-
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
 using System;
 using Microsoft.AspNet.Mvc.Core;
 using Microsoft.AspNet.Mvc.ModelBinding;

test/Microsoft.AspNet.Mvc.Razor.Test/RazorPageCreateModelExpressionTest.cs

@@ -1,4 +1,6 @@
-
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
 using System;
 using System.IO;
 using System.Linq.Expressions;