MPI_COMM_SPAWN_MULTIPLE was just wrong. This commit renames a few
variables to make their meaning a bit more clear and fixes up all
known issues with converting a 2D array of Fortran strings to a set of
C-style argv vectors.
Fixes trac:2420.
This commit was SVN r23217.
The following Trac tickets were found above:
Ticket 2420 --> https://svn.open-mpi.org/trac/ompi/ticket/2420