Grid analyzer updated with log and output

With using some code from other files we can analyze the resolution
phantom quite efficiently now.
Adapt logfile name
Write out contrast-stretched images

The Radiography-Detector now writes out contrast-stretched images, since
those are easier to look at with the other analysis scripts.
Also adapted for consistent log file and output file naming.
Additionally, we now select the images based on max(Image), no longer
the mean(Image).