combine precise positioning with pregrading

This mr includes code to use pregrading when the pages have been realigned. thanks to the realigning, corner markers are not needed for pregrading and are therefore removed. Also, since the realigning is so consistent, the parameters for pregrading have been tuned for better results.

Note: this mr relies on mr !20 (merged) and needs to be merged first. It also makes use of the highlighting feature, which is not in develop (yet).