Many fixes to keep this from crashing due to changes in parameters, loading/clearing etc. Add functionality for hiding/showing ROIs associated with Crystal area used for calibration. Disable Find Crystals button until we can determine a better way to specify the regions automatically for now at least, the crystal arrays overlap and have low intensity (making it hard to find the lines to fit). Added a menu item which allows showing the data points to be used in calibration. There are some significant regions of overlap that should probably be avoided. This should help find them.