* backend/plustek-pp.h backend/plustek-pp_ptdrv.c backend/plustek_pp.c:
fixed "not homing" problem, the sensor did not return when
the driver gets the _IOCTL_STOP command
fixed compilation issue for kernels > 2.6.15
fixed compiler warning conditions
All the supported CanoScan devices should work now correctly.
Moved the Plustek parallelport support into a separate backend: plustek_pp.
Added new backend for Plustek ASIC 9600x/9800x based parallelport scanner.