Added IFileSystem

Fixed issue with last merge

src/Umbraco.Tests/IO/PhysicalFileSystemTests.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using NUnit.Framework;
+using Umbraco.Core.IO;
+using Umbraco.Tests.BusinessLogic;
+
+namespace Umbraco.Tests.IO
+{
+    [TestFixture]
+    internal class PhysicalFileSystemTests : AbstractFileSystemTests
+    {
+        public PhysicalFileSystemTests()
+            : base(new PhysicalFileSystem(AppDomain.CurrentDomain.BaseDirectory,
+                "/Media/"))
+        { }
+
+        protected override string ConstructUrl(string path)
+        {
+            return "/Media/" + path;
+        }
+    }
+}