Fixed the "Missing time information in save .IM file"  reported by Dr. Rusinek.  This was due to the time written in "absolute value" and using the scientific notation some important lower digits were truncated.  Switched to the regular "double float" format by using %lf option in fprintf().

Documented the latest version of the semi-automatic IDIF tool.

Extending the IDIF functionality so several seeds can be specified covering branches of the Carotid Artery to create larger ROI and thus more reliable Input Function. Since the IDIF function is very fast this is done simply by calling procedure several time and OR-ing corresponding ROIs to create the final one.

Verified that the Macro Seed for the IDIF may be specified on any of the orthogonal projections.`It makes it possible to specify the Macro Seed on the Axial projection where Carotid artery can be found easily.