Daemonize signal-watcher.

src/signals.rkt

@@ -5,6 +5,7 @@
 	 start-restart-signal-watcher)
 
 (require reloadable)
+(require "daemon.rkt")
 
 (define (poll-signal signal-file-name message handler)
   (when (file-exists? signal-file-name)
@@ -13,7 +14,8 @@
     (handler)))
 
 (define (start-restart-signal-watcher)
-  (thread
+  (daemon-thread
+   'restart-signal-watcher
    (lambda ()
      (let loop ()
        (flush-output) ;; Somewhat gratuitous; help ensure timely stdout logging