Merge branch 'Modernise_Interaction_1' into 'master'

src/Cxx/Interaction/Assembly.cxx

src/Cxx/Interaction/CallBack.cxx

src/Cxx/Interaction/CallBack.md

src/Cxx/Interaction/CallData.cxx

src/Cxx/Interaction/CallData.md

src/Cxx/Interaction/ClientData.cxx

src/Cxx/Interaction/DoubleClick.cxx

src/Cxx/Interaction/EllipticalButton.cxx

src/Cxx/Interaction/EllipticalButton.md

src/Cxx/Interaction/Game.cxx

src/Cxx/Interaction/ImageClip.cxx

src/Cxx/Interaction/ImageClip.md

src/Cxx/Interaction/ImageRegion.cxx

src/Cxx/Interaction/ImageRegion.md

src/Cxx/Interaction/InteractorStyleTerrain.cxx

src/Cxx/Interaction/InteractorStyleUser.cxx

src/Cxx/Interaction/InteractorStyleUser.md

src/Cxx/Interaction/KeypressEvents.cxx

src/Cxx/Interaction/KeypressEvents.md

src/Cxx/Interaction/KeypressObserver.cxx