ISO-9660: Implement file extraction

Author: hounsell

TotalImage.IO/FileSystems/ISO/IsoFile.cs

@@ -70,7 +70,9 @@ public override void MoveTo(string path)
         /// <inheritdoc />
         public override Stream GetStream()
         {
-            throw new NotImplementedException();
+            long offset = ((Iso9660FileSystem)FileSystem).PrimaryVolumeDescriptor.LogicalBlockSize * Record.ExtentOffset;
+            var fileStream = new PartialStream(FileSystem.GetStream(), offset, Record.DataLength);
+            return fileStream;
         }
 
         /// <summary>

TotalImage/frmMain.cs

@@ -2053,7 +2053,11 @@ private void ExtractFiles(IEnumerable<TiFileSystemObject> items, string path, Se
                 }
 
                 using (var destStream = new FileStream(Path.Combine(path, file.Name), FileMode.Create))
+                using (var fileStream = file.GetStream())
+                {
+                    fileStream.Position = 0; // reset position to zero because CopyTo will only go from current position
                     file.GetStream().CopyTo(destStream);
+                }
 
                 if (Settings.CurrentSettings.ExtractPreserveDates)
                 {