hdf5_msb

[svn-r23366] Removed the H5Pset_dxpl_multi and H5Pget_dxpl_multi functions from the
library.  The intended functionality for them was never fully implemented
and they are fundamentally broken.

The functions were removed from the C and C++ interfaces.  They were not
exported in the Fortran interface.

Tested on: jam(c++/fortran/hl)

I tested using check-vfd to ensure the multi VFD still works properly.
There is no reason to test this on other machines or on parallel.