mdns: Fix/Update Windows mdns code

This syncs the application side with the updates in the mdns.h file
from: https://github.com/mjansson/mdns/
and does things according to the specs. (build up info from both A, AAAA and
SRV records), not just assuming that the DNS server is the host.

Signed-off-by: Robin Getz <[email protected]>