./manage_all.sh: add force-stop

manage_all.sh

@@ -10,11 +10,14 @@ for vm in output/*/; do
 		'stop')
 			echo system_powerdown | ncat -U "$vm/monitor.sock"
 			;;
+		'force-stop')
+			echo quit | ncat -U "$vm/monitor.sock"
+			;;
 		'attach')
 			remote-viewer "spice+unix://./$vm/spice.sock" &
 			;;
 		*)
-			echo >&2 "Usage: $0 (start | stop | attach)"
+			echo >&2 'Usage: $0 (start | [force-]stop | attach)'
 			exit 1
 			;;
 	esac