Log Message:
Update graphics/sane-backends to sane-backends-1.0.24.
ok wiz@.

Changes:
* Significant enhancements to pixma, genesys, kodakaio, fujitsu, canon_dr.
* Minor updates, bugfixes or scanners added in several backends.
* Added new testsuite
* 51 new scanner models supported.
* USB support improvements.
* Improved build system (mingw64, bug fixes, default pthread on Linux).
* Documentation updates.
* Bugfixes.