subclasses of vtkPropCollection.  This breaks a dependency that was introduced
between common and graphics. vtkActor2DCollection, vtkActorCollection and
vtkVolumeCollection now support an additional API of GetNextActor(),
GetLastActor(), GetNextVolume(), etc.  vtkPropCollection no longer supports
GetNextItem() and GetLastItem(); they have been replaced with GetNextProp() and
GetLastProp().

ENH: Build process has been changed such that the Tcl and Java versions of
the VTK libraries only contain the Tcl and Java and bindings.  They no longer
include all of the VTK objects as well.  To build applications that use
a Tcl of Java library you will need to link with both the Tcl library and
the standard VTK library, i.e. -lVTKGraphicsTcl -lVTKGraphics.  This reduces
the size of the disk images for the libraries by about half.