The child processes of pid 1 were being reparented to pid 1, causing an
infinite loop. This change fixes the problem by adding a hook that runs in
the last thread about to exit in a process. When pid 1 exits, the hook will
prevent more processes and threads from being created, and then broadcast
kill all processes and threads. The hook is not run in LastPrayer(), as that
function runs in a worker thread and it can't block waiting for another
thread to run LastPrayer() in the same thread.