[vtkusers] NEW tcl example

[Dean Inglis]

Hi all,

after a long time since posting vtkSplineWidget, 
and having read some recent posts, I created a 
tcl demo hybridized from:

/Hybrid/Testing/Cxx/TestSplineWidget.cxx 
/Examples/GUI/Tcl/ImagePlaneWidget.tcl
/Hybrid/Testing/Cxx/TestOrientationMarkerWidget.cxx

The demo shows how to do a profile plot of
image data sampled along a spline curve.

I also added a new feature to vtkAnnotatedCubeActor
so that face text pairs can be rotated in instances
wherein the text may appear "upside down," or some
other unusual orientation, depending on how one
interprets the orientation of the data set that 
the marker should be reflecting.

hope this helps...

Dean