hdf5_ep

[svn-r3867] 
Purpose:
     bug fix Adding more features
Description:
    Bugs: 1) hdf4 dimensional scale data can be none, but the dim name can still defined by users, so number of hdf4 dimensional names and number of object reference may be different
    Previously, this problem is not considered.

          2) SDcheckempty will return true when fill value is set to HDF4 SDS, and then fill value information is lost
          3) check whether SDS have fill value set although SDcheckempty return true.
             Use H5Psetfillvalue and H5Dcreate in HDF5 part, still needs to wait for the new development of HDF5 and also need to investigate whether this part of code has bugs.
    New features: compressed SDS will get compressed with gzip when it is converted. That will save some space.
    [describe the bug, or describe the new feature, etc]
Solution:
     See  above and design document
Platforms tested:
    eirene(linux)
    [machines you have tested the changed version.  This is absolute
    important.  Test it out on at least two or three different platforms
    such as Big-endian-32bit (SUN/IRIX), little-endian-32(LINUX) and
    64-bit (IRIX64/UNICOS/DEC-ALPHA) would be good.]