boxtools on raspberry pi

- rename to_system to apu_system / cm3_system /cm4_system
- fixes in router
- firewall may be switched off
- firewall is a parameter of router, also used when no routing is configured.

display.py

@@ -7,7 +7,6 @@ import threading
 import re
 import queue
 from utils import MainIf
-from subprocess import Popen, PIPE
 from configparser import ConfigParser
 
 # display tty device