Enhancement Request: GZIP support (tar mode)

[Pwntus]

Writing down how I implemented ZIP at first. As discussed, weights are not good for ZIP compression due to their "noisy" structure - decompressing with ZIP adds ~50-60 seconds.

1. Import compress/gzip.
2. When extracting, first create a uncompressed stream before feeding to the tar reader:

func extractTarFile(buffer *bytes.Buffer, destDir string) error {
  uncompressedStream, err := gzip.NewReader(buffer)
  if err != nil {
    return err
  }

  tarReader := tar.NewReader(uncompressedStream)
  // ...
}

[tempusfrangit]

This should be much easier to implement now as a consumer, do we want it?

[tempusfrangit]

Ignore the reference from #158, that was incorrect.