it was (BitmapText::LoadFromNode, etc. called it). This worked because
REGISTER_ACTOR_CLASS called it before the object was downcasted to an Actor.
We then re-called Actor::LoadFromNode from ActorUtil::LoadFromActorFile;
this worked because all it did was re-run Actor init (causing double
calls to Init) and not the whole actor.
(first half fix: make Actor::LoadFromNode virtual and add comment)