Use a separate thread to watch for dead processes

[Kolaer]

trafficstars

Should help with #63

"Works on my machine" (c), but I have a somewhat unusual setup and I don't have enough knowledge of the project to properly test this (I've run a bunch of manual tests, but I'm still not convinced that this works in all configurations).

@s3rius can you look into this and test on your setup as well? We tried a similar approach together and I remember that it didn't work for some reason.

[s3rius]

Sure. Let me check it.

[s3rius]

Guess it doesn't work. I just created a redis broker and tried to modify a file several times. I don't know why is it happening, because everything seems to be ok in the code. But here's the screencast:

https://user-images.githubusercontent.com/18153319/228361195-2834597e-4c4c-45e4-8288-b43810af5cde.mp4