SIGINT handler should wait for stop to complete before exit

red.js

@@ -333,8 +333,7 @@ process.on('uncaughtException',function(err) {
 });
 
 process.on('SIGINT', function () {
-    RED.stop();
-    // TODO: need to allow nodes to close asynchronously before terminating the
-    // process - ie, promises
+    RED.stop().then(function() {
         process.exit();
     });
+});