Merge ModelsBuilder in, NuGet dies on circ dependencies now

src/Umbraco.ModelsBuilder/ImplementContentTypeAttribute.cs

@@ -0,0 +1,20 @@
+using System;
+
+namespace Umbraco.ModelsBuilder
+{
+    // NOTE
+    // that attribute should inherit from PublishedModelAttribute
+    // so we do not have different syntaxes
+    // but... is sealed at the moment.
+
+    /// <summary>
+    /// Indicates that a (partial) class defines the model type for a specific alias.
+    /// </summary>
+    /// <remarks>Though a model will be generated - so that is the way to register a rename.</remarks>
+    [AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = false)]
+    public sealed class ImplementContentTypeAttribute : Attribute
+    {
+        public ImplementContentTypeAttribute(string alias)
+        { }
+    }
+}