[vtkusers] New graph structures

[Jeff Baumes]

Hello all,

I wanted to give everyone a heads-up that there is a newly refactored
vtkGraph and vtkTree headed into VTK in the next few days. Among the
major changes are:

* Iterator-based access to edges
* vtkGraph subclasses from vtkDataObject instead of vtkPointSet
* vtkGraph's implementation is much more like that of the boost graph library
* Separate classes vtkDirectedGraph and vtkUndirectedGraph instead of
a Directed flag
* Mutable classes vtkMutableDirectedGraph and
vtkMutableUndirectedGraph used for building graphs

Jeff

-- 
Jeff Baumes, Ph.D.
R&D Engineer, Kitware Inc.
(518) 371-3971 x132
jeff.baumes at kitware.com