Add prediff for test3DLulesh to filter error codes in slurm.
Merge branch 'master' of https://github.com/chapel-lang/chapel into deal-with-3d-lulesh
Improve filter for test3DLulesh.

based on review by @ronawho
Merge pull request #378 from thomasvandoren/deal-with-3d-lulesh

Add prediff for test3DLulesh to filter error codes in slurm.

I verified this worked on an XC with slurm launcher and on my mac with no launcher.