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.
This is to avoid breakage when upgrading or downgrading git-annex with a
process running that uses the interface. It's better to keep the
compatability code for a few years than worry about such breakage.
This commit was sponsored by Brett Eisenberg on Patreon.
This old code will now be useful for git-annex beyond the assistant.
git-annex won't use the CheckTransferrer part, and won't run transferkeys
as a batch process, and will want withTransferrer to not shut down
transferkeys processes. Still, the rest of this is a good fit for what I
need now.
Also removed some dead code, and simplified a little bit.
This commit was sponsored by Mark Reidenbach on Patreon.
