Get public ip address by use of special DNS

[D9ping]

Make it possible to get the public ip address by use of a DNS service. Like the special myip.opendns.com dns request that returns the public ip adres if using opendns dns server(208.67.222.222).
Look if there are other DNS servers offering something like this too.

[D9ping]

o-o.myaddr.l.google.com on ns1.google.com will return own ip as TXT record.
Different record type. A TXT record is probably a safer choice.

[D9ping]

Postponed for 2.0 release.

[Davejob09]

Hello