Added some useful filtering functions.
Added some useful filtering functions.


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