Fix up some DNS verbiage to make it consistant.

Fix up default route selection by
a) Forcing user to explicitly chose 'dhcp' as a mechanism for
specifying a default route, rather than guessing based on one or more
interfaces being configured by dhcp.
b) If the user specified default route does not work, re-present the
existing default route rather than losing it.
c) Move default route selection to after nameserver activation so the
user can specify a hostname as the default route.
Change /etc/netstart so that /etc/mygate wins if a default route was
already specified (i.e. by dhcp).
ok deraadt@.

src/etc/netstart

@@ -1,6 +1,6 @@
 #!/bin/sh -
 #
-#	$OpenBSD: netstart,v 1.85 2002/05/16 20:48:25 todd Exp $
+#	$OpenBSD: netstart,v 1.86 2003/02/16 23:25:40 krw Exp $
 
 # Returns true if $1 contains only alphanumerics
 isalphanumeric() {
@@ -275,6 +275,7 @@ fi
 # /etc/mygate, if it exists, contains the name of my gateway host
 # that name must be in /etc/hosts.
 if [ -f /etc/mygate ]; then
+	route delete default > /dev/null 2>&1
 	route -n add -host default `cat /etc/mygate`
 fi