vchoi_fork

[svn-r4334] 
Purpose:
    1) fix the implementation of image according to image specfication
    2) fix two bugs of SDS implemention. the first one is
        to handle the unlimited SDS with the first dimensional size set to 0.
        the second one is to change the way how HDF5 dataset is written.
Description:
    1) mapping 24-bit image to 3D arrays instead of 2D compound datatype.
    2) previously forgot considering unlimited SDS with the size set to 0.
    3) H5P_set_buffer seems not working well for a extremely small size.
Solution:
    1) see above.
    2) add a special case to deal with this.
    3) don't use H5Pset_buffer.
Platforms tested:
     RedHat Zoot 6.2