with newer automake.
* backend/Makefile.am, tools/sane-config.in: Add missing
$GPHOTO2_LDFLAGS so library can be found.
* tools/Makefile.am: Add mising $SCSI_LIBS to sane-find-scanner.
Add tools/openbsd to distribution package.
* include/Makefile.am: include files should have been installed
under sane/ directory when converted to automake.
* doc/Makefile.am: Cleanup. Use automake's built in support to
install docs within subdirectories.