vchoi_fork

[svn-r22128] Purpose: Fixed bug 4279
Description:
    Closed various HDF5 objects in DataSet::getInMemDataSize and
    Attribute::getInMemDataSize to remove some memory leaks.
Platforms tested:
    Linux/32 2.6 (jam)
    Linux/64 2.6 (amani)
    SunOS 5.10 (linew)