hdf5_ep

[svn-r3015] Purpose:
    Bug fixes
Description:
    Patch things back up from incompletely changing some variables in
    yesterday's code cleanup, this should fix the compiler errors that Kent
    and Bill have found in the CVS version of the code.

    Also, fix a bug buried in the datatype conversions when compound datasets
    were nested inside an array or variable-length datatype.  Internally
    require that any datatype which contains a compound datatype sets the
    "need_bkg" conversion flag so a background buffer to pass to the compound
    datatype conversion is allocated.

Platforms tested:
    FreeBSD 4.2 (hawkwind) & Solaris 2.6 (baldric)