hdf5doc

Description:
    Added new macro descriptions:  H5Dopen and H5Dcreate.
    Renamed existing functions:  H5Dopen and H5Dcreate renamed to 
        H5D<same_name>1.
    Deprecated H5Dextend in favor of H5Dset_extent.
    Incorporated full function description for H5Dset_extent;
        original description stated only that the function is identical 
        to H5Dextend except for being able to reduce dimension sizes.
Tested:  Firefox