Read information about optical resolution and line distance from scanner

instead of hardcoded values.
Add support for color depth > 8 bits per channel.
Backend version is now 0.36

backend/epson.desc

@@ -10,7 +10,7 @@
 ;
 
 :backend "epson"                  ; name of backend
-:version "0.1.35"                 ; version of backend
+:version "0.1.36"                 ; version of backend
 :status :beta                     ; :alpha, :beta, :stable, :new
 :manpage "sane-epson"             ; name of manpage (if it exists)
 :url "http://www.freecolormanagement.com/sane"        ; backend's web page
@@ -73,6 +73,9 @@
 :comment "with TPU"
 :interface "USB"
 
+:model "Perfection 1240"
+:interface "SCSI USB"
+
 :model "Expression 636"
 :interface "SCSI"
 

backend/epson.h

@@ -222,6 +222,7 @@ struct Epson_Device {
 	SANE_Bool ADF;			/* ADF is installed */
 	SANE_Bool focusSupport;		/* does this scanner have support for "set focus position" ? */
 	SANE_Bool color_shuffle;	/* does this scanner need color shuffling */
+	SANE_Int  maxDepth;		/* max. color depth */
 
 	SANE_Int  optical_res;		/* optical resolution */
 	SANE_Int  max_line_distance;