This commit adds some glue code to support the C++ bindings and
updates the bindings to use the new glue code. This protects our
internal headers (which are C99) from C++. This is done as a quick
workaround to compilation errors when the legacy C++ bindings are
requested.
Fixesopen-mpi/ompi#2055
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>