Changed over Action to use PluginTypeResolver to find and instantiate IActionHandlers and included a unit test.

src/umbraco.cms/PluginTypeResolverExtensions.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Generic;
+using Umbraco.Core;
+using umbraco.BusinessLogic.Actions;
+using umbraco.businesslogic;
+using umbraco.interfaces;
+
+namespace umbraco.cms
+{
+	/// <summary>
+	/// Extension methods for the PluginTypeResolver
+	/// </summary>
+	public static class PluginTypeResolverExtensions
+	{		
+
+		/// <summary>
+		/// Returns all available IActionHandler in application
+		/// </summary>
+		/// <param name="resolver"></param>
+		/// <returns></returns>
+		internal static IEnumerable<Type> ResolveActions(this PluginTypeResolver resolver)
+		{
+			return resolver.ResolveTypes<IActionHandler>();
+		}
+
+	}
+}