hdf5: Add mpi support

Optionally, build the parallel version of hdf5.
hdf5: Offer openmpi version of the package
hdf5: Optional enableShared flag

Required by h5py in mpi mode.
mpi4py: New package, version 1.3.1

Python wrapper for the message passing interface standard.

Currently building without mpe, or vampir-trace support.
h5py: New package, version 2.3.1

A pythonic interface to the hdf5 library. It also supports parallel hdf5.
openmpi: Optional configure flags

 * Activate support for the Sun Grid Engine
 * Pass PATH/LD_LIBRARY_PATH pointing to the current mpi installation
   to other processes by default.
Merge pull request #3316 from aherrmann/pr_mpi

MPI support for HDF5 and SGE support for OpenMPI