hdf5_ep

[svn-r3194] 
Purpose:
     bug fix
Description:
    1. zeroing out memory before using the memory buffer
    2. before wrongly using Vquerysize API of HDF4 to obtain
       the real file size of record type in HDF4. Actually Vquerysize will
       return the real data type size in Memory. That will cause the object
       reference difference on Cray which file size is not equal memory size.

Solution:
    1. using h4toh5ZeroingMemory function to zero out memory.
    2. calcuating the real file size of vdata record in the converter instead of
       using Vquerysize HDF4 API.
Platforms tested:
    Cray J90, arabica, eirene