Deoldify Vapoursynth filter

[Dan64]

Now with the "custom" preset it is possible to set the custom parameters.
But I expect that when preset is different from "custom" is called the function "ddeoldify_main()" with in input the selected presets, but instead are called the functions ddeoldify() and ddeoldify_stabilizer() as in the "custom" preset.

Moreover there is a typo in setting the custom parameter smooth_p, in the list is passed the value none instead of string "none".

Dan