Deoldify Vapoursynth filter

[Selur]

I decided to don't deliver it becasuse on my tests this version was slower.

I suspect it will be slower if more scene changes are detected. + I think this option should be added.

In this case the sc_threshold need to be set to a lower value, because usually the logo will cover most of mask region and the change in the mask_region are less than on full

from the argumentation, I would have gone for higher values for the threshold, not lower ones

I will release a new RC version with this comment fixed and a change in a parameter name, which will allow to control another interesting feature, that I'm still testing.

Looking forward to it, probably won't get around to test it until tomorrow evening. (visiting parents tomorrow after work)

Cu Selur