Finally fixed cancelling, which I broke some time ago in the quest
for speed. FB620P still doesn't abort nicely (firmware bug?).
* doc/sane-canon_pp.man: Added notes on FB620P problems.
* doc/descriptions/canon_pp.desc: Bumped version number.
backend/canon_pp-dev.h: Many changes: Bug fixes, less memory leaks (none left now?), more relaible, faster. Biggest changes are speculative reads (ask scanner to read more while data processing
occurs) and more reliable sending of commands. Slight performance
increase over previous version.
* doc/sane-canon_pp.man: Added discussion noting that scanning
greyscale in green is bad for colour.
possible, then feeds data to frontend. Results in large speed
increase in ECP mode. Also fixed problems with saned compatibility.
* backend/canon_pp.h: Added bytes_sent to scanner data structure.
* doc/sane-canon_pp.man: Discuss hardware problems at high
resolutions.
(should have done this last time.. and should those dates be in GMT or something? I now have a change committed on a date after the change that came after it.. we're world-leaders here in Aus.)