[sane-devel] Lexmark backend

[stef]

	Hello,

	I have updated the lexmark backend with the experimental version. This brings 
the following features:
	- offset and gain calibration
	- software shading correction
	- arbitrary scan size within the physical scan area
	- support for X12xx series scanners
	- support for Dell A920
	- support for other models of X11xx with a different sensor

	It has these limitations:
	- hardware image compression isn't implemented for the X12xx,
		leading to slow scans when on USB1.1
	- modes below 300 dpi may have issues for X12xx on USB2.0
	- 1200x600 dpi mode is only implemented for the X1185

	In case of problem, please send to the list, or to me the logs 'scanimage' 
will output when these environment variables are set:
SANE_DEBUG_LEXMARK=255
SANE_DEBUG_LEXMARK_LOW=255

	To have even more debug, you can compile some extra code with:
CFLAGS=-DDEEP_DEBUG ./configure --your-configure-options...

Regards,
	Stef