hdf5_chunking_query_bmr

[svn-r5386] Purpose:
    Bug Fix

Description:
    Currently, only process 0 is writing attribute data to a file.  This is
    incorrect, because the raw data for attributes is cached in memory until
    the object header is written and other processes are not able to read the
    correct attribute information.

Solution:
    Have all processes participate in writing the attribute data.

Platforms tested:
    IRIX64 6.5 (modi4)