Added LDAC_LIN optimization script to ProductionToolsvim

Made a small tool for measuring pixel threshold spread as a function of LDAC_LIN. It was somewhat described in my presentations here and here. As it stands now, it is just a shell script (with many options) that runs threqu+scurve many times and a root macro that analyzes the results. It is currently located in my personal repository. Since everything else I found under ProductionTools was just C++ headers and .cc files, I put my script under an additional repository ProductionTools/LDACLINCalibration. I could do it in some different way if you have any suggestions. I add this directory to PATH in setup.sh so the shell script is runnable from someone's working directory. However, the root macro should be copied directly to the working directory before running it (or I need to update it a little bit).