synthetic darks as new option

[salvaGiner]

I 've tested darks with the app and compared to synthetics darks of that night and the results seem to be better with synthetic darks taken on the current night images. This can be a good option for next version. The synthetic darks script only need to get the 5 or 10 darker images of that night. Create the mean image and rest that image to the current night images before creating timelapse keogram and strartrails

[EricClaeys]

@salvaGiner,
What is a "synthetic dark"?

Would you please post an image using traditional darks and an image (ideally the same image) using a synthetic dark? I'd like to see the difference.

Also, please run ls -l ~/allsky/darks.
Lastly, what type of camera do you have?