MCWrapper with slurm

[aaust]

There is only a skeleton structure for using MCWrapper directly with slurm batch systems:

gluex_MCwrapper/gluex_MC.py

Lines 761 to 763 in 6c1642f

	#====================================================
	#Takes in a few pertinant pieces of info. Submits to SLURM
	#This was originally targetting NERSC. Then JLab announced a switch to slurm. And then swif did it. If there is demand this should be finished up

Since most university clusters use slurm, I believe the demand to complete this project is there now.

Ideally, there should be "slurm" and "slurmcont" options for BATCH_SYSTEM together with documentation and/or example config files.