Merge topic 'apple-driver-message-warn-once'

dab78865 vtkOpenGLPolyDataMapper: warn about broken gl_PrimitiveID once

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Utkarsh Ayachit <utkarsh.ayachit@kitware.com>
Merge-request: !568