Fixes #3769: Move r29177 to v1.7 branch (enable mxm2 by default on)

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r29177 [[BR]]
enable mxm2 by default on np>=0
reviewed by yossi
cmr:v1.7.3:reviewer=jsquyres

r29178 [[BR]]
enable mxm2 from np>0
reviewed by yossi
cmr:v1.7.3:reviewer=jsquyres
Fixes #3790: Move r29226 to v1.7 (cleanup pmi warning)

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r29226 [[BR]]
Silence warnings about pointer casting
Fixes #3791: Move r29227 to v1.7 branch (Only connect the first time)

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r29227 [[BR]]
Only connect the first time thru the Torque launch, remove stale code

cmr:v1.7.3:reviewer=jsquyres