Fixes #3835: Move r29405 to v1.7 branch (fix mpi_abort and modex_recv for direct launch)

****   NOTE   ****
This CMR only takes the part of r29405 that dealt with cleanup
of MPI_Abort for direct launch processes. Changes to the OPAL
db storage system were deferred to v1.7.4 as they require
additional changes included in another CMR.

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r29405 [[BR]]
*****   THIS INCLUDES A SMALL CHANGE IN THE MPI-RTE INTERFACE   *****

Fix two problems that surfaced when using direct launch under SLURM:

1. locally store our own data because some BTLs want to retrieve 
   it during add_procs rather than use what they have internally

2. cleanup MPI_Abort so it correctly passes the error status all
   the way down to the actual exit. When someone implemented the
   "abort_peers" API, they left out the error status. So we lost
   it at that point and *always* exited with a status of 1. This 
   forces a change to the API to include the status.

cmr:v1.7.3:reviewer=jsquyres:subject=Fix MPI_Abort and modex_recv for direct launch
Fixes #3838: Move r29412 to v1.7 branch (hostname may not NULL-terminate the)

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r29412 [[BR]]
hostname may not NULL-terminate the string if the buffer is too small.

Thanks to Kevin M. Hildebrand for catching this.

cmr=v1.7.3:reviewer=jsquyres
Fixes #3839: Move r29415 to v1.7 branch (remove duplicate (thanks Jeff))

No review required for platform files

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r29415 [[BR]]
remove duplicate (thanks Jeff)
add epoll
cmr=v1.7.3:reviewer=jsquyres