Fixes #4386: Move r31058 to v1.7 branch (Continue to resolve priority issues.)

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r31058 [[BR]]
Continue to resolve priority issues. Cleanup the case of forced termination in mpirun during launch processing by ensuring we can respond to socket closures, and ensuring that the remote daemons correctly close their sockets when terminating.

Jeff: please test a variety of conditions to ensure we get this right

cmr=v1.7.5:reviewer=jsquyres
Fixes #4388: Move r31062 to v1.7 branch (Fix --enable|disable-oshmem configure switch)

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r31062 [[BR]]
Fix --enable|disable-oshmem configure switch

* Fixed the AC_ARG_ENABLE for the oshmem option.
* Fixed the AM_CONDITIONALs values for the projects.
* Re-added (and slightly simplified) the use of PROJECT_OSHMEM in
  various Makefile.am's to disable building OSHMEM stuff

Submitted by Jeff, reviewed and approved by Ralph.

cmr=v1.7.5:reviewer=ompi-gk1.7