Deoldify Vapoursynth filter

[Dan64]

Here another interesting case: https://imgsli.com/MjcxMDI3

In this example the colors provided by HAVC without DeepEx are very wrong, using DeepEx it is possible to improve the result (RefMerge=1 is the best in this case).

I released another RC where I introduced a check on the directory specified to store the images, if are not found reference frames is raised an Error.

Dan