Vcs3d unstructured grid plot improvements

Fixes a hang that occurs in communication with sub-procs when plotting an unstructured grid variable in vcs3D.  Also adds some diagnostics.
Charles,
Yes, you can comment out all the diagnostic print statements.   The purpose of this 'printParameterValues' call is to be able to determine the current set of parameter values when running a script.   The saveState method is called from the 's' key event.   I use this feature when constructing demo scripts.

> @@ -361,6 +361,7 @@ def changeButtonActivations(self, activation_list ):

>
>      def saveState(self, **args):
>          print "Save State"
> +        self.printParameterValues()


do we really want to print every parameter values when we save? Or was this just for you for debugging?