hdf5_ep

[svn-r6392] Purpose:
    Update

Description:
    Folded in Quincey's changes to the caching stuff. (Stole the code
    from the H5FDmpio driver).

    Roughed in some code for doing a read from the SAP. Also roughed in
    code for doing a write. However, the write requires an OID, which I'm
    not sure how to pass down into the driver (maybe via the
    dxpl_id?...but then it has always to be set before calling one of
    these routines...).

    Removed some of the global variables which were there because of the
    FPHDF5 stuff...

    Removed the H5Ofphdf5.* stuff from the Makefile.in, since I'm pretty
    sure it's going away and I don't want to waste time updating that
    module if that's the case...so just don't compile it.

Platforms tested:
    Linux