Add a resolv.conf option to specify the order in which getaddrinfo

PF_UNSPEC queries are made. While there change the default from inet6
first then inet4 to inet4 first then inet6, this prevents the many
people with IPv4 only connectivity from constantly trying to contact
IPv6 addresses, and also unbreaks many ports who don't use getaddrinfo
right.
ok deraadt@, plenty of cheering in the room wrt the idea, not loud
enough complaining from the v6 crowd.

src/include/resolv.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: resolv.h,v 1.16 2005/03/30 02:58:28 tedu Exp $	*/
+/*	$OpenBSD: resolv.h,v 1.17 2009/06/04 18:06:35 pyr Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -136,6 +136,9 @@ struct __res_state {
 	int	retry;			/* number of times to retransmit */
 	unsigned int	options;	/* option flags - see below. */
 	int	nscount;		/* number of name servers */
+	int	family[2];		/* specifies which address
+					 * families will be queried and
+					 * in which order */
 	struct sockaddr_in
 		nsaddr_list[MAXNS];	/* address of name server */
 #define	nsaddr	nsaddr_list[0]		/* for backward compatibility */