fix bug 0013676: vtkLightActor crashes if the light is not positional

Change-Id: I7b45af49eec2d19565660c01d9bd1fbfe08e5204
Merge topic 'bug0013676' into master

25f91796 fix bug 0013676: vtkLightActor crashes if the light is not positional
Fix struct/class definition warning

Ensure consistency between cxx and h file for the internal structure.

Change-Id: Ibb41575e2ba9231972b48758b4c61de2dab4d381
Merge topic 'vtkweb-warning-fix' into master

804c8faa Fix struct/class definition warning