with this commit, we remove the implicit DNSName string constructors, which hid many...

with this commit, we remove the implicit DNSName string constructors, which hid many many issues, including passing all DNS query packets as DNS domain names and converting them back again (WOW). To slightly compensate, we added an ostream operator<< to make printing of DNSNames easier.
This commit will start a world of pain and it isn't even done yet. Specifically forwarding to another nameserver is broken now (was broken already, we tried to push a :port number into a DNSName and parse it again). The webserver API was lovingly DNSNamed but will also likely have changes in case sensitivity, . termination and other things.