What: Add basic algorithms for the various non-blocking intercommunicator
collectives and add support for MPI_Comm_dup_with_info, MPI_Comm_create_group,
and MPI_Comm_idup. These features are targeted for 1.7.4.
When: Commiting this next Wednesday. This may not give much time for feedback
but there will be plenty of time for this to soak on the trunk (and be subject
to MTT) before it goes into 1.7.x.
Why: MPI-3.0 compliance!
See the attached patches for additonal details.