UFW software firewall for Malcolm ISO should automatically open ports for syslog

[mmguero]

#354 added support for syslog ingestion. However, in the ISO install of Malcolm the ports will not be open in the firewall, and require this workaround (depending on the ports specified):

$ sudo ufw allow 514/tcp
Rule added
$ sudo ufw allow 514/udp
Rule added

We could just add 514/tcp and 514/udp to the default firewall rules but the user is allowed to specify the port, so we can't just do that.

The thing probably to do is to add an entry to config/includes.chroot/etc/sudoers.d/ to allow the user (technically users of the docker group or, maybe, the network group) the run ufw as sudo without password, then adjust it when they set the ports either in the install.py script or upon startup.

For now I will document that the user needs to run the UFW command manually.