NodeDisc removal event dispatching to Twig at least partially working. Fixed bug in adding branch to branchesArray of Twig.  Not sure if garbage collection on NodeDiscs working right now.  The Twigs are never getting removed right now, though.
NodeDisc and Twig removal are now working properly.  Twig removal is animated.  Don't remove the Timer Event listener on Forest once we've hit max Twigs since as we remove Twigs we'll allow new ones to get added.