vchoi_fork

[svn-r6106] Purpose:
    Code cleanup, Feature enhancement

Description:
    Improve hashing algorithm to not generate as many clashes.

    Avoid using H5MD_realloc when changing the size of a chunk on disk.
    Instead, use H5MF_free followed by H5MF_alloc, which avoids copying the
    information from the space for the previous chunk to the space for the
    new chunk, since we are going to overwrite the chunk with new data anyway.
    This change should both improve I/O performance in situations where
    compressed chunks are being overwritten as well as reduce the space used
    in the file during that situation.

    Cleaned up error handling in a few cases.

    Removed old debugging printf()s.

Platforms tested:
    Tested h5committest {arabica (fortran), eirene (fortran, C++)
	modi4 (parallel, fortran)}

    FreeBSD 4.7 (sleipnir)