aesx660: fix spelling of define name
aeslib: improve frame-assembling routines

Some scanners provide hardware assistance in frame assemling, i.e.
horizontal and vertical offset to previous frame is provided. This
commit improves code to utilise that assistance. Sensors without
hardware assistance will use software algorithm, which was also
improved to do search in horizontal direction.
upeksonly: add support for 147e:1001 device