Dynamic Averaging function: corrected defect due to the conversion of the Real-volume to 32-bit representation.

Modified the "Linear concentration" formula, to compensate for initial "bright" timepoints.
In patient RE this resulted to Max concentration increasing from 0.005 to 0.03


Modified the RoiStats4D dialog, so that the linear concentration of ROI and fitted model could be displayed overlaid.

MainMenu>ROI>Skeleton:  added UI level function for ROI skeleton detection.  Simplistic algorithm works well in 2D case.  3D case would require new more complex algorithm.

PET brain "Ridge Segmentation" function:   finalized interface and functionality for 2D and 3D cases.  Simplistic skeletonization algorithm that works well in 2D, for some reason is not performing well in 3D and would require more time to integrate more precise 3D skeletonization.
Therefore, due to a limited time available,  "Process slices individually" option is always on in 3D case for the time being.