Kill all tasks on shutdown and startup

BindsTo will kill all the tasks when systemctl stop box is executed.
But when restarted, it keeps the tasks running. Because of this behavior,
we kill the tasks on startup and stop of the box code.

src/cloudron.js

@@ -66,7 +66,7 @@ function uninitialize(callback) {
 
     async.series([
         cron.stopJobs,
-        platform.stop
+        platform.stopAllTasks
     ], callback);
 }
 
@@ -109,6 +109,9 @@ function notifyUpdate(callback) {
 
 // each of these tasks can fail. we will add some routes to fix/re-run them
 function runStartupTasks() {
+    // stop all the systemd tasks
+    platform.stopAllTasks(NOOP_CALLBACK);
+
     // configure nginx to be reachable by IP
     reverseProxy.writeDefaultConfig(NOOP_CALLBACK);