h4h5tools

Purpose:
     1.bugs fix
     2. new features
Description:
     1. when converting lone vds to HDF5, put Vgetid inside the if block,
	under some circumstances(if doesn't valid), it will generate infinite loop.
     2. It's legal to create an empty vdata inside HDF4, however, some HDF4
        vdata interface Vquery... will not work for empty vdata, that will
         cause converter fail.
     3. Add two functions H4toH5objinfo and H4toH5obj_nameinfo for reimplementing
         h4toh5 utility with h4toh5 library.
Solution:
     1. move vgetid out of if block.
     2. add a checking point to check the size of vdata, if vdata size is 0,
        converter will not convert this vdata.
Platforms tested:
     linux 2.2.18