[sane-devel] USB detection changed: please test

[Henning Meier-Geinitz]

Hi,

I've just changed the way the detection of USB scanners works. This
was necessary because of "scanimage -L" taking very long (20-80
seconds) to find USB scanners.

If you have USB scanners, please test if everything works as before.
No changes in backends or other files should be necessary.

A snapshot can be downloaded from here:
http://www.meier-geinitz.de/sane/snapshots/

Basically, I've moved the detection from sanei_usb_find_devices to
sanei_usb_init. That means, the (possibly slow) detection is only done
once per backend instead of once per supported scanner.

Further more, the device files are now checked for existence before
opening them. This should make systems which use devfs faster.

Bye,
  Henning