Add: feature to gracefully shutdown/wake kafka

sleep_hook is called both before suspend and after system wakes up from suspend.

Before suspend, it stops Zookeeper, broker, mirror services along with all the
logging services.

After waking up, it restarts everything.

Author: wang701

misc/sleep_hook.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+
+if [ "${1}" == "pre" ]; then
+	# Do the thing you want before suspend here, e.g.:
+	systemctl stop mirror
+	systemctl stop zookeeper
+	systemctl stop gps-log@remote
+	systemctl stop gps-log@gps
+	sync
+elif [ "${1}" == "post" ]; then
+	# Do the thing you want after resume here, e.g.:
+	systemctl restart zookeeper
+	systemctl restart mirror
+  systemctl restart gps-log@remote
+  systemctl restart gps-log@gps
+	systemctl restart gps-log-watchdog
+fi