hdf5_chunking_query_bmr

[svn-r6308] Purpose:
    Bug fix

Description:
    Currently, when the library encounters an object header message that isn't
    know, it fails to open that object in the file.

Solution:
    Allow the library to skip over the unknown object header message and
    continue to process the remaining messages, in the hope that the skipped
    message isn't important later.  If it is important, it will be caught at
    a higher level of the library.

Platforms tested:
    FreeBSD 4.7 (sleipnir)