Add AI_FQDN flag to getaddrinfo(3). Prompted by discussions with djm@

about cert checking in OpenSSH.  Man page wording tweaks thanks to
jmc@.
ok henning@, jmc@; positive feedback from djm@, ajacoutat@
Committing now to reuse guenther@'s libc minor bump instead of
cranking it again, as suggested by deraadt@.

src/include/netdb.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: netdb.h,v 1.27 2009/06/02 16:47:50 jasper Exp $	*/
+/*	$OpenBSD: netdb.h,v 1.28 2011/04/05 00:46:06 matthew Exp $	*/
 
 /*
  * ++Copyright++ 1980, 1983, 1988, 1993
@@ -155,9 +155,10 @@ struct	protoent {
 #define AI_NUMERICHOST	4	/* don't ever try hostname lookup */
 #define AI_EXT		8	/* enable non-portable extensions */
 #define AI_NUMERICSERV	16	/* don't ever try servname lookup */
+#define AI_FQDN		32	/* return the FQDN that was resolved */
 /* valid flags for addrinfo */
 #define AI_MASK \
-    (AI_PASSIVE | AI_CANONNAME | AI_NUMERICHOST | AI_NUMERICSERV)
+    (AI_PASSIVE | AI_CANONNAME | AI_NUMERICHOST | AI_NUMERICSERV | AI_FQDN)
 
 #define NI_NUMERICHOST	1	/* return the host address, not the name */
 #define NI_NUMERICSERV	2	/* return the service address, not the name */