Apparently the first commit (59ae429972)
did not include all files.
Furthermore the used script tended to produce funny results in certain
cases. This has been fixed and as a result thereof a few more changes
were made in this second run.
Qt 4 used a different implementation because QDnsLookup was introduced in Qt 5.
Unlike the complete implementation, the Qt 4 compatible one only supported simple lookups (e.g. hostname -> IP address).
