Detections slider issue

[kevev]

On v0.1.0 when sliding "Detections / s" all the way to the left, the frames stop advancing when "Source" = a video file.

This also causes 2 other issues:

Most options/buttons to be disabled after the app is restarted.

The window app window will disappear when closing it, but the scoresight.exe process stays running in the background.