Allow LIGO to force all checkpoints to local ckpt server #3580

Only when knob ALWAYS_USE_LOCAL_CKPT_SERVER is true.
improve mpich2 script, such that mpi jobs within the parallel universe
have a hope of actually working. For htcondor-inf 33782.
Merge branch 'V8_0-branch' into V8_1_5-branch
Merge branch 'V8_1_5-branch'