CompoundNodule : Avoid creation of duplicate child nodules.
CompoundNodule : Avoid creation of duplicate child nodules.

This occurred when a CompoundNodule was constructed from a `childAddedSignal()`, via the OSLCode node changing it's metadata. In this case the CompoundNodule would create all the children it needed in the constructor, connect to `childAddedSignal()`, and then create a duplicate as `childAdded()` was called from the (already in flight) signal.

GafferHQ/gaffer,GafferHQ/gaffer,hradec/gaffer,lucienfostier/gaffer,ivanimanishi/gaffer,johnhaddon/gaffer,chippey/gaffer,lucienfostier/gaffer,GafferHQ/gaffer,hradec/gaffer,andrewkaufman/gaffer,chippey/gaffer,boberfly/gaffer,andrewkaufman/gaffer,hradec/gaffer,johnhaddon/gaffer,GafferHQ/gaffer,appleseedhq/gaffer,boberfly/gaffer,lucienfostier/gaffer,chippey/gaffer,GafferHQ/gaffer,ivanimanishi/gaffer,johnhaddon/gaffer,hradec/gaffer,boberfly/gaffer,johnhaddon/gaffer,ImageEngine/gaffer,appleseedhq/gaffer,appleseedhq/gaffer,lucienfostier/gaffer,andrewkaufman/gaffer,ivanimanishi/gaffer,chippey/gaffer,boberfly/gaffer,ImageEngine/gaffer,johnhaddon/gaffer,hradec/gaffer,ivanimanishi/gaffer,ImageEngine/gaffer,andrewkaufman/gaffer,ImageEngine/gaffer,appleseedhq/gaffer,andrewkaufman/gaffer