do not intsall rtadvd.conf into /etc, it is not required to use it

(rtadvd will derive the configuration from kernel settings).
make it clearer that rtadvd.conf is not necessary, in manpage.
sync with kame.

src/etc/Makefile

@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.116 2000/10/10 15:34:31 provos Exp $
+#	$OpenBSD: Makefile,v 1.117 2001/01/21 15:11:18 itojun Exp $
 
 TZDIR=		/usr/share/zoneinfo
 LOCALTIME=	US/Pacific
@@ -18,7 +18,7 @@ BIN1=	bootptab changelist ccd.conf csh.cshrc csh.login csh.logout \
 	ipf.rules ksh.kshrc locate.rc man.conf monthly motd mrouted.conf \
 	myname ipnat.rules netstart networks newsyslog.conf passwd.conf \
 	phones printcap protocols rbootd.conf rc rc.conf rc.local \
-	rc.securelevel rc.shutdown remote rpc rtadvd.conf security services \
+	rc.securelevel rc.shutdown remote rpc security services \
 	shells syslog.conf weekly etc.${MACHINE}/disktab dhclient.conf \
 	mailer.conf
 

src/etc/rtadvd.conf

@@ -1,26 +0,0 @@
-#	$OpenBSD: rtadvd.conf,v 1.3 2000/03/17 17:34:43 itojun Exp $
-
-# common definitions.
-# Note: All of the following parameters have default values defined
-#       in specifications, and hence you usually do not have to set them
-#       by hand unless you need special non-default values.
-#       You even do not need to create the configuration file. rtadvd
-#       would usually work well without a configuration file.
-#       See also: rtadvd(8)
-
-#default:\
-#	:chlim#64:raflags#0:rltime#1800:rtime#30000:retrans#1000:\
-#	:pinfoflags#192:vltime#3600000:pltime#3600000:mtu#1500:
-#ether:\
-#	:mtu#1500:tc=default:
-
-# per-interface definitions.
-#   IPv6 prefixes are configured in this part. However, rtadvd
-#   automatically learns appropriate prefixes from the kernel's routing
-#   table and advertises the prefixes, so you don't have to configure
-#   this part, either.
-#   If you don't want the automatic advertisement, invoke rtadvd with
-#   the -s option and configure this part by hand.
-
-#ef0:\
-#	:addrs#1:addr="3ffe:0501:ffff:0000::":prefixlen#64:tc=ether: