Add a fire-and-forget executor for pipelines.

lib/Predis/Pipeline/FireAndForgetExecutor.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Predis\Pipeline;
+
+use Predis\Network\IConnection;
+
+class FireAndForgetExecutor implements IPipelineExecutor {
+    public function execute(IConnection $connection, &$commands) {
+        foreach ($commands as $command) {
+            $connection->writeCommand($command);
+        }
+        $connection->disconnect();
+
+        return array();
+    }
+}