Get rid of all memory leaks due to removeAllListeners() are not calle…

…d. Executor and QueryCommand mostly

src/Io/Connection.php

@@ -179,6 +179,12 @@ public function close()
         }
 
         $this->emit('close');
+        /**
+         * MemoryLeak: Remove all listeners from executor, so it
+         * will be removed from memory when connection
+         * is closed.
+         */
+        $this->executor->removeAllListeners();
         $this->removeAllListeners();
     }
 

src/Io/Executor.php

@@ -23,6 +23,28 @@ public function isIdle()
 
     public function enqueue($command)
     {
+        /**
+         * MemoryLeak: Make sure removeAllListeners is called on commands,
+         * otherwise they might stay in memory for ever.
+         */
+        $command->on(
+            'error',
+            function () use ($command) {
+                $command->removeAllListeners();
+            }
+        );
+        $command->on(
+            'success',
+            function () use ($command) {
+                $command->removeAllListeners();
+            }
+        );
+        $command->on(
+            'end',
+            function () use ($command) {
+                $command->removeAllListeners();
+            }
+        );
         $this->queue->enqueue($command);
         $this->emit('new');