PATCH: [0/4] Splitting TWAIN_32 and adding gphoto driver

[Marcus Meissner]

Hi,

This series of patches splits up the sane specific parts of
twain_32 into the controller part (twain_32) and sane specific
driver part (sane.ds). It also implements a working gphoto
driver (gphoto.ds).

TWAIN itself has a concept of:

- DSM / Data Source Manager ... A controller that manages
  the datasources and their lifetimes.

  This was and is still found in twain_32.dll

- DS / Data Source(s) ... A multitude of datasources, usually
  per camera / scanner drivers found in %windir%/TWAIN_32/ and
  subdirs.

  Up to now this was also in twain_32.dll, but this series
  splits it out.

Drivers:
- sane.ds: The old twain_32.dll sane code split off from twain_32.dll.

- gphoto.ds: New gphoto importer code, originating from the old sane.ds
  as example.


Autodetection:
- Autodetection has been moved from twain_32.dll to the drivers.

  -> twain_32.dll itself is no longer dependend on libsane and actually
  has only minimal knowledge of sane and gphoto2 (the driver names ;)

- Detection of multiple devices is in the DG_CONTROL/DAT_IDENTITY/MSG_GET
  calls of sane.ds and gphoto2.ds. A little hidden channel detects multiple
  scanners / cameras by calling above function multiple times.

The code is ready for WINE inclusion (tm).

Ciao, Marcus