Add option to turn off calendar via env variables settable via cron.

Ie: ``CALENDAR=0'' will turn it off which is useful for machines with
no local users that do not run YP.

src/etc/daily

@@ -1,6 +1,6 @@
 #!/bin/sh -
 #
-#	$OpenBSD: daily,v 1.17 1997/01/17 06:18:19 millert Exp $
+#	$OpenBSD: daily,v 1.18 1997/02/19 16:49:18 millert Exp $
 #	From: @(#)daily	8.2 (Berkeley) 1/25/94
 #
 PATH=/bin:/usr/bin:/sbin:/usr/sbin:/usr/local/bin
@@ -110,8 +110,13 @@ fi
 }
 
 echo ""
-if [ -d /var/yp/binding -a ! -d /var/yp/`domainname` ]; then
-	echo "Not running calendar, (yp client)."
+if [ -d /var/yp/binding -a ! -d /var/yp/`domainname` -o "X$CALENDAR" = X0 ]
+then
+	if [ "X$CALENDAR" = X0 ]; then
+		echo "Not running calendar, (disabled)."
+	else
+		echo "Not running calendar, (yp client)."
+	fi
 else
 	echo "Running calendar."
 	calendar -a