Remaining temp files

[HolyGit12]

crf-search does not delete all temp files after finishing the search.
The both files of the last sample are staying in the temp folder. The temp folder won't be removed.
(Windows version but I guess that this does not matter)

[9Oc]

I am also experiencing this after the newest version [0.9.1] with the sample-encode command as well.

[alexheretic]

It's possible a recent ffmpeg process is still alive and prevents cleanup. I recently removed logic that would, a little too eagerly, kill ffmpeg so this makes sense.

So I'll look at adding graceful shutdown of these child processes which should resolve this.