NTFileStore: SecurityDescriptor: Added Length property

SMBLibrary/NTFileStore/Structures/SecurityInformation/SecurityDescriptor.cs

@@ -1,4 +1,4 @@
-/* Copyright (C) 2014 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
+/* Copyright (C) 2014-2017 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
  * 
  * You can redistribute this program and/or modify it under the terms of
  * the GNU Lesser Public License as published by the Free Software Foundation,
@@ -67,5 +67,13 @@ namespace SMBLibrary
         {
             throw new NotImplementedException();
         }
+
+        public int Length
+        {
+            get
+            {
+                throw new NotImplementedException();
+            }
+        }
     }
 }