Deoldify Vapoursynth filter

[Dan64]

I updated the filter with the color stabilizer.
There is a new list of parameters called "color_stabilizer"

color_stabilizer: list = [False, 21, 'left', False]

:param color_stabilizer:   parameters for the temporal color stabilizer
                                 [0] : colstab_enabled (bool), if true the filter is enabled
                                 [1] : colstab_nframes, number of frames to be used in the stabilizer, range[3-31]
                                 [2] : colstab_mode, type of average used by the stabilizer: range['left', 'center', 'right']
                                 [3] : colstab_scenechange, if true the futures frames will not be used in case of scene change detection, range [True,False]

I don't know how Vapoursynth can use the future frames if they has not been colored yet.
To be conservative, as default I adopted the "left average".

I also changed the name of parameter "ddcolor_weight" in "merge_weight".

I attached the new source code.

Dan