hdf5_chunking_query_bmr

[svn-r19712] Purpose:
    Fixed h5diff to handle variable-length strings in a compound dataset 
    correctly. Also variable-length string array in a compound dataset.
    Bug #1989.
    

Description:
    Garbage values were displayed when h5diff compared variable-length 
    strings (or string array) in a compound type dataset. 


Tested:
 jam (linux32-LE), amani (linux64-LE), heiwa (linuxppc64-BE), tejeda (Mac32)