New Layer control dialog: Added the "Info" button handler.

"Hover over ROI atlas" functionality was added. When there is an Atlas-like combination of ROIs is present, mouse cursor position is analyzed and the name of the single ROI layer is displayed that present at the mouse coordinate.

ROI compression\RAM allocation:  fixed major inefficiency defect, so that the RAM requirement for the 174 ROI atlas was reduced from 1GB down to 20 MB.

Old Layer Control dialog:  fixed the crash when  number of layers was exceeding the maximum (21).