adding example runit-style service directory

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

examples/var_service/ifplugd_if/ifplugd_handler

@@ -0,0 +1,15 @@
+#!/bin/sh
+# parameters:
+# $1: interface
+# $2: state
+
+if test -d "/var/service/dhcp_$1"; then
+	if test x"$2" = x"down"; then
+		echo "Downing /var/service/dhcp_$1"
+		sv d "/var/service/dhcp_$1"
+	fi
+	if test x"$2" = x"up"; then
+		echo "Upping /var/service/dhcp_$1"
+		sv u "/var/service/dhcp_$1"
+	fi
+fi