hdf5_ep

[svn-r3741] Purpose:
    Improvment
Description:
    H5config.h and H5pubconf.h are generated by configure.  It does
    not have the #ifndef _H5config_H ... #endif guard to prevent
    duplicated definitions if it is included more than once.
    It is messy to try make configure to put in those guards.
Solution:
    HDF5 has set an internal rule that H5public.h includes H5pubconf.h
    and H5private.h includes H5config.h.  Source files should NOT include
    H5config.h or H5pubconf.h directly but include it via H5public.h or
    H5private.h respectively.   The #ifndef ... #endif in the H5public.h
    and H5private.h would prevent repeated definitions from repeated
    include.

    Adjusted H5FDstream.c and H5FDstream.h to follow this rule.
Platforms tested:
    modi4, eirene.