clean up "Add" menubar categoes on the 3d object side via the following:

SceneObject now defaults to a category of "misc"
getCategoryOfClass now checks parent classes for what categories they hold so that variants can inherit
categories are in one of a few rough groups and subgroups depending on actual mapper needs/usages

Engine/source/T3D/player.h

@@ -697,6 +697,7 @@ protected:
 
 public:
    DECLARE_CONOBJECT(Player);
+   DECLARE_CATEGORY("Actor \t Controllable");
 
    Player();
    ~Player();