Removed unsupported functions from header.
Removed unsupported functions from header.

Some functions were defined in the header but never implemented. They have been
removed now.

RWTH-HPC/PnMPI,RWTH-ELP/PnMPI,RWTH-ELP/PnMPI,RWTH-ELP/PnMPI,RWTH-HPC/PnMPI,RWTH-HPC/PnMPI