Prevent setting the end_time of a running job to a value in the past,
even if the requested time_limit would imply such an end time.
Add "#include <stdlib.h>" to a couple of files - I have no idea when
the #includes vanished from.

   as is with the SLURM package

   of srcdir

 o define MIN in macros.h

 o srun only sets environment variable SLURM_CPUS_PER_TASK if it was
   explicitly set by the user (-c).

min+ by default.

papers in different subdirectories.

Some word-smithing and clean-up.