Sandia National Laboratories recently changed management from the
Sandia Corporation to the National Technology & Engineering Solutions
of Sandia, LLC (NTESS). The copyright statements need to be updated
accordingly.
Also made the TextAnnotation classes conform better to VTK-m coding
style. Specifically, changed the order of words in subclass names (e.g.
TextAnnotationBillboard instead of BillboardTextAnnotation) and broke
out each subclass into its own header/source files.
