saned requires write access scanner USB bus for its process and
to usblp/bind in order to rebind multifunctional printers back
to usblp (for printing with p910nd).
A hotplug script monitor new USB devices for scanners. Scanners
are detected by searching /usr/share/sane/<vendor>-<backend>.usbid
for the device product_id.
The package saned creates user saned:scanners. Access is granted to
group scanners.
The default xinetd conf was updated to run as saned:scanner.
sane-daemon pkg now has a postinst trigger that runs udevtrigger for
granting perms where there are connected scanners during installation.
Existing hotplug scripts from hplip were removed. They were mostly
useless.
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>