Cactus Code Thorn PunctureTracker
Thorn Author(s)     : Michael Koppitz <koppitz@aei.mpg.de>
                      Erik Schnetter <schnetter@cct.lsu.edu>
                      Peter Diener <diener@cct.lsu.edu>
Thorn Maintainer(s) : Erik Schnetter <schnetter@cct.lsu.edu>
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Purpose of the thorn:

Time integrate the shift at the location of the punctures to follow the
location of the punctures.