Use more markup and improve table formatting.

lib/libc/sys/accept.2

@@ -1,4 +1,4 @@
-.\"	$NetBSD: accept.2,v 1.30 2013/08/02 14:10:46 elric Exp $
+.\"	$NetBSD: accept.2,v 1.31 2013/08/02 20:13:09 wiz Exp $
 .\"
 .\" Copyright (c) 1983, 1990, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -142,13 +142,16 @@ function behaves exactly like
 but it also allows to set the following
 .Fa flags
 on the returned file descriptor:
-.Bl -column SOCK_NONBLOCK -offset indent
+.Bl -tag -width SOCK_NOSIGPIPEXX -offset indent
 .It Dv SOCK_CLOEXEC
 Set the close on exec property.
 .It Dv SOCK_NONBLOCK
 Sets non-blocking I/O.
 .It Dv SOCK_NOSIGPIPE
-Return EPIPE instead of raising SIGPIPE.
+Return
+.Er EPIPE
+instead of raising
+.Dv SIGPIPE .
 .El
 .Pp
 It can also temporarily replace the signal mask of the calling thread if