added reconnect() method to db drivers
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index 6558112..74cfff4 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -91,6 +91,25 @@
 	// --------------------------------------------------------------------
 
 	/**
+	 * Reconnect
+	 *
+	 * Keep / reestablish the db connection if no queries have been
+	 * sent for a length of time exceeding the server's idle timeout
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	function reconnect()
+	{
+		if (mysqli_ping($this->conn_id) === FALSE)
+		{
+			$this->conn_id = FALSE;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Select the database
 	 *
 	 * @access	private called by the base class