Machine readable output for Keyserver query

It's a reference to https://github.com/openpgp-keychain/openpgp-keychain/issues/259. I've followed RFC documents linked in mentioned issue and tested it deeply. However, I'm new to this project, so I'd be very grateful for support and pointing out my mistakes :).

Despite of implementing machine readable queries, I've had to do minor fixes in convertFingerprintToHex (avoid printing unnecessary zeros) and convertKeyIdToHex32bit (ignore converting empty strings) methods.
Also I've added separate function for converting algorithm integer ID to String, to avoid code duplication.