Added FnSceneShape createChild, extracted from expandOnce.
Added FnSceneShape createChild, extracted from expandOnce.

davidsminor/cortex,lento/cortex,davidsminor/cortex,goddardl/cortex,hradec/cortex,appleseedhq/cortex,goddardl/cortex,davidsminor/cortex,hradec/cortex,lento/cortex,appleseedhq/cortex,hradec/cortex,davidsminor/cortex,goddardl/cortex,lento/cortex,appleseedhq/cortex