Fixed error with calling stop method.

flight/Engine.php

@@ -292,7 +292,9 @@ class Engine {
         }
 
         // Allow post-filters to run
-        $this->after('start', array($this, 'stop'));
+        $this->after('start', function() {
+            $this->stop();
+        });
 
         // Route the request
         while ($route = $this->router()->route($this->request())) {

flight/core/Dispatcher.php

@@ -134,6 +134,7 @@ class Dispatcher {
      * @param callback $callback Callback function
      * @param array $params Function parameters
      * @return mixed Function results
+     * @throws \Exception
      */
     public static function execute($callback, array &$params = array()) {
         if (is_callable($callback)) {