Deoldify Vapoursynth filter

[Dan64]

I need to change DeOldify and DDColor to work with VideoFrame instead of VideoNode.
To do that I need to create a custom version of DDColor since I cannot change the DDColor repository
I'm the owner of DeOldify filter so I could change vs-deoldify.
But I prefer to don't touch vs-deoldify because now is stable.

So I will build a new filter where I will introduce some new feature respect to vs-deoldify: scene detection, reference frame generation, temporal frame stabilization, and probably I will reuse some of the pre/post filters already developed for vs-deoldify. 

This new filter will be slower than vs-deoldify, and probably will be only a little more stable but with more vivid colors, so vs-deoldify will be still a viable alternative for users not having powerful GPUs.

Dan