1. Modified the imports
2.Background to SlateGray
3.default size to default
4.modified the arg parse help

1) Simplified the regular expressions
2) Comments in the examples are now handled correctly
3) C++ interface and implementation files are separately processed

1) Command line arguments simplified.
2) Indexing to allow tracing back to original data points.
3) We now drop rows with nan in them.
4) Enabling the vtkCameraOrientationWidget.

See: https://discourse.vtk.org/t/shadowlightsdemo-extents-of-shadows-light-frustum-darkened-areas/3410