hdf5_chunking_query_bmr

[svn-r13883] Description:
    Fixed bugs w/VL-datatype fill values for chunked dataset storage.

Tested on:
    Mac OS X/32 10.4.9 (amazon)
    FreeBSD/32 6.2 (duty)
    FreeBSD/64 6.2 (liberty)
    Linux/32 2.6 (chicago)
    Linux/64 2.6 (chicago2)