volume rendering for VisAD now works on Windows

The Java3D folks told me that Texture3D does not work on
Windows and won't any time soon.  So the VisAD volume
rendering implementation no longer uses it.  We have tested
it on several Windows and Solaris systems and it works.
Furthermore, visad/examples/Test61.java now makes a more
interesting shape.

Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI  53706
hibbard@xxxxxxxxxxxxxxxxx  608-263-4427  fax: 608-263-6738