Fixes #4672: Move r31878 to v1.8 branch (OSHMEM: fix - use real)

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r31878 [[BR]]
OSHMEM: fix - use real mkey for atomics for rc/dc

fixed by Roman, reviewed by Vasily

cmr=v1.8.2:reviewer=ompi-rm1.8

r31881 [[BR]]
OSHMEM: add compat to prev mxm version

fixed by ROman, reviewed by MikeD

Refs: #4672
Fixes #4673: Move r31880 to v1.8 branch (OSHMEM: fix compiler warnings)

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r31880 [[BR]]
OSHMEM: fix compiler warnings

fixed by Roman, reviewed by Miked

cmr=v1.8.2:reviewer=ompi-rm1.8
Fixes #4675: Move r31882 to v1.8 branch (plm/alps: better workaround for the)

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r31882 [[BR]]
plm/alps: better workaround for the noisy cray pmi implementation

This commit is a slightly better workaround to prevent mesages of
the form:
[unset]:_pmi_alps_get_apid:alps_app_lli_put_request failed
[unset]:_pmi_alps_get_appLayout:pmi_alps_get_apid returned with error: Bad file descriptor

It works by completely disabling PMI in the application process when using
mpirun. This should not be an issue for any apps.

cmr=v1.8.2:reviewer=rhc