Added `--disable-mpi-fortran` in building of OpenMPI.

* openmpi/jamfile: `--disable-mpi-f77` and `--disable-mpi-f90` command-line
                   options was replaced by `--disable-mpi-fortran` because
                   the formers are no longer valid.
Merge pull request #105 from Cryolite/fix/openMPI

Added `--disable-mpi-fortran` in building of OpenMPI.