Overlay mask working properly with static mask or video mask.
- made new masks.py file that we can use to consolidate other mask functions from main render code
- Overlay mask NOW WORKS WITH CADENCE. I made the function switchable between PIL rgb and np bgr and inject the function during cadence and for normal saves
- I didn't use old code. I just made this work myself.
Fixed one-off issue with hybrid video where the first frame was duplicated. (it became obvious when doing overlay video masking)
re-commented a few lines, removed some whitespace