Check for __res_query in libresolv
Changeset 74d6f2447f59a08c breaks builds here (Debian Jessie), because
__res_query is not found...
--- a/configure.ac Mon Jan 11 22:23:23 2016 +0100
+++ b/configure.ac Mon Jan 25 18:35:10 2016 +0100
@@ -135,6 +135,7 @@
dnl +--------------------------------------------------------+
AC_CHECK_LIB(nsl,gethostbyname)
AC_CHECK_LIB(socket,socket)
+AC_CHECK_LIB(resolv,__res_query)
AC_CHECK_LIB(resolv,res_query)
dnl +--------------------------------------------------------+