Draft support DNSSEC + DANE

This series of patches adds support for DNSSEC + parsing of DANE structures. 

Changes:
* To add support for sending a query that will set the flags needed by dnssec I had to add the new ares_create_query2().

* To determine the servers to use when dnssec is requested, it uses /etc/resolv-sec.conf, to avoid issues with programs overwritting the existing resolv.conf (e.g., vpn or dhcp servers).