getdns_query: add -K option to attach pinsets to getdns_contexts.
getdns_query: add -K option to attach pinsets to getdns_contexts.

smogali/getdns,smogali/getdns,huitema/getdns,shane-kerr/getdns,huitema/getdns,shane-kerr/getdns,shane-kerr/getdns,smogali/getdns,huitema/getdns,huitema/getdns,smogali/getdns,shane-kerr/getdns