add more variables for start-stop-daemon and supervise-daemon options

Add the following variables to expose more arguments that can be passed
to start-stop-daemon or supervise-daemon:

- directory will be passed to --chdir
- error_log will be passed to --stderr
- output_log will be passed to --stdout
- umask will be passed to umask

This is for #184.

sh/start-stop-daemon.sh

@@ -44,9 +44,13 @@ ssd_start()
 	eval start-stop-daemon --start \
 		--exec $command \
 		${chroot:+--chroot} $chroot \
+		${directory:+--chdir} $directory \
+		${output_log+--stdout} $output_log \
+		${error_log+--stderr} $error_log \
 		${procname:+--name} $procname \
 		${pidfile:+--pidfile} $pidfile \
 		${command_user+--user} $command_user \
+		${umask+--umask} $umask \
 		$_background $start_stop_daemon_args \
 		-- $command_args $command_args_background
 	if eend $? "Failed to start ${name:-$RC_SVCNAME}"; then

sh/supervise-daemon.sh

@@ -24,12 +24,16 @@ supervise_start()
 	# to work properly.
 	eval supervise-daemon "${RC_SVCNAME}" --start \
 		${retry:+--retry} $retry \
+		${directory:+--chdir} $directory  \
 		${chroot:+--chroot} $chroot \
+		${output_log+--stdout} ${output_log} \
+		${error_log+--stderr} $error_log \
 		${pidfile:+--pidfile} $pidfile \
 		${respawn_delay:+--respawn-delay} $respawn_delay \
 		${respawn_max:+--respawn-max} $respawn_max \
 		${respawn_period:+--respawn-period} $respawn_period \
 		${command_user+--user} $command_user \
+		${umask+--umask} $umask \
 		$supervise_daemon_args \
 		$command \
 		-- $command_args $command_args_foreground