Automatic Build Test: added subtest for the  PET "tau-ridges" segmentation.

Dialog Parametric Map calculation:  made the linear (T1W) concentration conversion consistent with the other parts of the FireVoxel.

IDIF functionality:  made a more User-convenient approach when unambiguous 4D volume is selected for the IDIF extraction.  Previously such layer had to be explicitly selected.

Restored the RoiStats4D dialog after the IDIF function is automatically calculated.

"Liver DCDI workflow" - added vessel names for AIF and VIF extraction functionality to clarify the meaning of the layers in the Layer Control Dialog and in the Dynamic Parametric Map calculation.

IDIF function:  when Auto-Direction is specified (f.e. Portal Vein),  the optimal direction is chosen by the intensity integral at the Peak timepoint, instead of simple count of the voxels in the vessel mask.