feature: Added powerdns dnsdist application (#7987)

* powerdns dnsdist app support

* fix conflict

* added doc

* fix new lines

* alphabetic order

* no data manipulation on host side
changed rrd from gauge to counter

html/includes/graphs/application/powerdns-dnsdist_queries_latency.inc.php

@@ -0,0 +1,52 @@
+<?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  2017 LibreNMS
+ * @author     Cercel Valentin <crc@nuamchefazi.ro>
+*/
+
+require 'includes/graphs/common.inc.php';
+$scale_min     = 0;
+$colours       = 'mixed';
+$unit_text     = 'Queries answer latency';
+$unitlen       = 6;
+$bigdescrlen   = 25;
+$smalldescrlen = 25;
+$dostack       = 0;
+$printtotal    = 0;
+$addarea       = 1;
+$transparency  = 33;
+$rrd_filename = rrd_name($device['hostname'], array('app', $app['app_type'], $app['app_id']));
+
+$array = array(
+    'latency_0_1' => array('descr' => '< 1ms', 'colour' => '58b146',),
+    'latency_1_10' => array('descr' => '1-10 ms', 'colour' => '4f9f3f',),
+    'latency_10_50' => array('descr' => '10-50 ms', 'colour' => '3d7b31',),
+    'latency_50_100' => array('descr' => '50-100 ms', 'colour' => '23461c',),
+    'latency_100_1000' => array('descr' => '100-1000 ms', 'colour' => '11230e',),
+    'latency_slow' => array('descr' => '> 1 sec', 'colour' => '727F8C',),
+);
+
+$i = 0;
+
+if (rrdtool_check_rrd_exists($rrd_filename)) {
+    foreach ($array as $ds => $var) {
+        $rrd_list[$i]['filename'] = $rrd_filename;
+        $rrd_list[$i]['descr'] = $var['descr'];
+        $rrd_list[$i]['ds'] = $ds;
+        $rrd_list[$i]['colour'] = $var['colour'];
+        $i++;
+    }
+} else {
+    echo "file missing: $rrd_filename";
+}
+
+require 'includes/graphs/generic_v3_multiline_float.inc.php';