hdf5

[svn-r26737] Purpose: Fix daily test failure
Description:
    - In DataType::DataType(const PredType& pred_type), using DataType::copy
    will invoke DataType::close() unnecessarily, which will produce undefined
    behavior.  Changed to call H5Tcopy directly, code reuse is not useful in
    this case.
    - Also, fixed CommonFG::childObjVersion to return expected value outside of
    an if/else block.
Platforms tested:
    Linux/ppc64 (ostrich)
    Linux/64 (platypus)
    Linux/32 2.6 (jam)