Add udev rule generation script for setting up multiple printers

(On one matterQ server / RPi).
Add script to load config from printcap

All config options used in /etc/matterq.conf can now be set per printer in
/etc/printcap.
Load the config from printcap into environment after /etc/matterq.conf

Therefore printcap overrides matterq.conf which remains the default.

Only need to add options to the printcap that vary between printers.