hdf5_ep

[svn-r10568] Purpose:
    Bug fix.

Description:
    The current HDF5 library call H5Tget_size when called by the filter
    does not give the correct disk size for varible-length and variable-length
    string. The filter needs to have another way, if possible, to get their
    sizes.

Solution:
    The filter can only solve this problem if varible-length and variable-length
    string is a member of compound datatype. The filter does not support the
    situation where an array datatype has variable-length or variable-length
    string as its base datatype.

Platforms tested:
    heping, shanti

Misc. update: