Done on unix, could not implement it on windows quite.
The signal library gets part of the way needed for windows.
But I had to open https://github.com/pmlodawski/signal/issues/1 because
it lacks raiseSignal.
Also, I don't know what the equivilant of getProcessGroupIDOf is on
windows. And System.Process does not provide a way to send any signal to
a process group except for SIGINT.
This commit was sponsored by Boyd Stephen Smith Jr. on Patreon.
