Cactus Code Thorn TerminationTrigger
Author(s)    : Christian D. Ott
Maintainer(s): Cactus team
Licence      : LGPL
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1. Purpose

This thorn watches the elapsed walltime.  If only n minutes are left
before the some limit set by the user, it triggers termination of the
simulation.  Termination is also triggered if a special file with a
special content exists.