hdf5_ep

[svn-r11755] Purpose: Code improvement

Description:
    There was a workaround for predefined types, in the C++ library,
    implemented when the C++ library was handling the reference
    counting of the object ids on its own.  Currently, the C++ library
    is using the available APIs from the C library for that purpose,
    and there were bugs reported involving that part of the C++ library.
    So, I decided to remove the workaround completely.

    Also, improved the use of std members.

Platforms tested:
    Linux 2.4 (heping)
    SunOS 5.8 64-bit (sol)
    Linux 2.4 w/PGI (colonelk)