Throws on unarchival

[mredig]

Every time I try to unarchive the nodejs server tarball, it throws an error (I decompress it first) triggering line 466 of KBTarUnarchiver.swift on commit ce026160f8f009275afd1cc8175a199aa3ec0072:

                case .other: // Unknown type - throw an error.
                    throw KBTarError.invalidTarType // <-- this one
                }

and prints out Error: The .tar file contains unsupported elements.

Both the OS unarchiver and SWCompression can handle it fine once uncompressed, so I don't think the file is corrupted.