Liver DCDI model:  adding two implementations of this model to the UI. 
The "Standard" variant, has exact implementation of the Sourbron's paper with the addition of the Exam length parameter and the variables {TotalFlow,fa,Ve,ki}.
The "Experimental" variant hosts new investigations, such as independently derived "Ta" arterial delay time.

Fixed the defect in   "Roi>Convert 3D to 4D" function.  DICOM-style headers were not properly constructed for a newly created 4D entity.