Security fix: unauthorized access (#10091)

* Security fix: unauthorized access
Affects nginx users:
Moved php files outside of public html directory (Apache was protected by .htaccess)

Affects all users:
Some files did not check for authentication and could disclose some info.
Better checks before including files from user input

* git mv html/includes/ includes/html
git mv html/pages/ includes/html/

includes/html/pages/device/port/plugins.inc.php

@@ -0,0 +1,24 @@
+<?php
+/*
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.  Please see LICENSE.txt at the top level of
+ * the source code distribution for details.
+
+ * @package    LibreNMS
+ * @subpackage webui
+ * @link       http://librenms.org
+ * @copyright  2018 PipoCanaja <pipocanaja@gmail.com>
+ * @author     PipoCanaja <pipocanaja@gmail.com>
+ */
+
+$pagetitle[] = 'Plugins';
+$no_refresh = true;
+?>
+
+<h3>Plugins</h3>
+<hr>
+<?php
+\LibreNMS\Plugins::call('port_container', [$device, $port]);
+