[Feature Request] Skip ranges of frames from processing

[flesler]

Until there's a sophisticated way to choose which faces to replaced. It's possible to handle cases where 2+ faces want to be replaced and only one is shown on each frame at the time.

One can run this once with a face and replace certain frames. Then run again with another face and another set of frames (potentially the exact opposite sometimes).

So I think it'd be very useful to be able to define ranges of frames to process and maybe a boolean flag to invert the ranges (for the cases where 2 faces are to be replaced and one is in a frame at all times).

It could go something like

python run.py --range 1-10 --range 15-20 --range 30 --invert-ranges

or maybe

python run.py --include 1-10 --include 15-20 --include 30 --invert-includes