Image downloader progress bar for saving files and refreshing stats

The final step for the image downloads could use a progress bar for saving files and refreshing stats. Downloading the images for the first time can take a very long time to process afterwards. So instead of displaying "Please wait", it would help with a progress bar there as well.

And speaking of… I have tried two clean installations downloading both the 10 and 15 Gb versions, and under both installations, this part of the process just kept on going and never resolved (even after 8+ hours).