used to set SLURM_CPUS_ON_NODE env var and compute memory limit.
We compare the allocated CPUs information passed in the job step 
credential (typically cores) and compare with the CPUs configured
on the node and scale the value as needed.

all job priorities are very low.

 I'll need to modify the test for systems with >1 ThreadPerCore configured

  found in testing that new code:
- avoid draining node if stdout/err file can't be created
- correction in logic for >1 thread per core in setting a job's SLURM_CPUS_ON_NODE env var
- Fix for uneven task distributions on heterogeneous clusters
  (e.g. 4 CPUs on the first node and 2 CPUs on the second,
  a task_count=2 resulted in cpus_per_task=3, and previously
  allocated both tasks to the first node, now does one task
  per node)

  (was using day of month=0 instead of 1) 

 Mostly a matter of moving some logic to a new module.

Changed the default age weight to zero in the mf plugin