#if OMPI_WANT_MPI2_ONE_SIDED and some automake conditionals. Also had
to add some AC_SUBSTs to eliminate part of mpif.h (otherwise the
"external" statements would have made undefined symbols).
All the MPI-2 one-sided functionality (including the skeleton
top-level MPI API functions that only invoke an MPI exception) can be
re-enabled with --enable-mpi2-one-sided.
This commit was SVN r3802.