up the StateSetManipulator and moved the initialization of locally cached states
into the handle method to ensure a representative version of the StateSet is captured
lighting and backface culling settings from the event handling code in StatesetManipulator
into public methods. The event handler now calls the public methods. This allows user code
to invoke this same functionality from non-keyboard event inputs without clashing with the
keyboard-invoked functionality."
From Robert Osfield, tweaks to the above to kepp the coding style the same as the rest of the OSG, also
made getPolygonMode() const, and updated the wrappers.
