Added IFileSystem

Fixed issue with last merge

src/Umbraco.Core/IO/IFileSystem.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+
+namespace Umbraco.Core.IO
+{
+    internal interface IFileSystem
+    {
+        void DeleteDirectory(string path);
+
+        void DeleteDirectory(string path, bool recursive);
+
+        IEnumerable<string> GetFiles(string path);
+
+        IEnumerable<string> GetFiles(string path, string filter);
+
+        IEnumerable<string> GetDirectories(string path);
+
+        string GetFullPath(string path);
+
+        string GetUrl(string path);
+
+        void DeleteFile(string path);
+
+        bool FileExists(string path);
+
+        bool DirectoryExists(string path);
+
+        void AddFile(string path, Stream stream);
+
+        void AddFile(string path, Stream stream, bool overrideIfExists);
+
+        Stream OpenFile(string path);
+
+        DateTimeOffset GetLastModified(string path);
+
+        DateTimeOffset GetCreated(string path);
+    }
+}