Add official support for PowerDNS and purge MyDNS
PowerDNS can be configured via direct database manipulation or via an API: https://doc.powerdns.com/md/httpapi/README/ Reason behind this Request: MyDNS had it's last update in 2006, MyDNS-ng in 2010. They are quite outdated.
Also, it seems that its easier to handle a DNS Servercluster with PowerDNS, also regarding DNSSEC