Update comment to describe why we must move two levels up (now includes the ForceSet/ConstraintSet) to access the BodySet, where dependencies were always located, prior to 4.0.
Update comment to describe why we must move two levels up (now includes the ForceSet/ConstraintSet) to access the BodySet, where dependencies were always located, prior to 4.0.

opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core