Klaus Kämpf authored Feb 20, 2015 and Stéphane Voltz committed Aug 31, 2015

This commit adds support for (slide) scanners based
on Pacific Image Electronics (PIE) oem scan hardware.

It is known to match the following USB scanners

  PIE PowerSlide 3600       Untested
  PIE PowerSlide 3650       Untested
  PIE PowerSlide 4000       Untested
  PIE PowerSlide 5000       Untested
  Reflecta CrystalScan 7200 Untested
  Reflecta ProScan 7200     Untested
  Reflecta DigitDia 4000    Untested
  Reflecta DigitDia 5000    Untested
  Reflecta DigitDia 6000    Ok

The backend is based on work by Jan Vleeshouwers and Michael Rickmann.

Special thanks to Stphane Voltz for the code review.

Add pieusb to backend/Makefile.am
Add pieusb to doc/Makefile.am
Add missing sanei/sanei_ir.c, sanei/sanei_ir.h, adapt Makefile.am
configure.ac: Add 'pieusb' to ALL_BACKENDS
ChangeLog: Add pieusb as new backend
Mark infrared functions as internal: sane_ir_* -> sanei_ir_*
sanei/sanei_ir.c: fix memory leaks
pieusb: rename cmdGetMode and cmdSetScanHead
	... to their sanei_pieusb_cmd_... equivalent
pieusb: rename definition_list_head to pieusb_definition_list_head
Add pieusb to AUTHORS
pieusb: copyright 2012-2015
pieusb: don't include sanei_thread.h