add save diagnostics function

add function so user is easily able to save their UPS details into a dummy-ups compliant .dev file, which the plugin developers can then request from the user to better identify problems with certain devices and the plugin itself.

source/nut/usr/local/emhttp/plugins/nut/NUTdetails.page

@@ -32,6 +32,8 @@ table.tablesorter tbody tr:nth-child(even) {
 <tbody id="nut_status"><tr><td colspan="4" style="text-align:center"><i class="fa fa-spinner fa-spin icon"></i><em>Please wait, retrieving UPS information...</em></td></tr></tbody>
 </table>
 
+<div style="font-size:x-small;font-weight:bold;"><a href="/plugins/nut/include/nut_status.php?diagsave=true&all=true">Save Diagnostics</a></div>
+
 <script>
 function getNUTstatus() {
   $.get('/plugins/nut/include/nut_status.php',{all:'true'},function(data) {

source/nut/usr/local/emhttp/plugins/nut/include/nut_status.php

@@ -29,6 +29,18 @@
 
 if (file_exists('/var/run/nut/upsmon.pid')) {
   exec("/usr/bin/upsc ".escapeshellarg($nut_name)."@$nut_ip 2>/dev/null", $rows);
+
+  if ($_GET['diagsave'] == "true") {
+
+  $diagstring = implode("\n",$rows);
+  header('Content-Disposition: attachment; filename="nut-diagnostics.dev"');
+  header('Content-Type: text/plain');
+  header('Content-Length: ' . strlen($diagstring));
+  header('Connection: close');
+  die($diagstring);
+
+  }
+
   for ($i=0; $i<count($rows); $i++) {
     $row = array_map('trim', explode(':', $rows[$i], 2));
     $key = $row[0];