Port the code to PHP 8.5.

Replace the short open tags and the removed functions (mcrypt, mysql_error,
salt-less crypt). Decode the reCAPTCHA reply as JSON, turn off mysqli
exceptions, drop stripslashes(), and default missing input values.
Fix the misplaced continue in prune_images().

publish/addeditor.php

@@ -1,4 +1,4 @@
-<? 
+<?php 
 if ( ! isset($_SERVER['HTTPS'])) {
    header('Location: https://' . $_SERVER["SERVER_NAME"] . $_SERVER['REQUEST_URI']);
 }
@@ -12,9 +12,9 @@ if (!isset($_SESSION['editor'])) {
   open_db('open');
   $table = "editors";
 
-  $username = $db->real_escape_string($_POST['username']);
-  $password = crypt($_POST['password']);
-  $email    = $db->real_escape_string($_POST['email']);
+  $username = $db->real_escape_string($_POST['username'] ?? '');
+  $password = $db->real_escape_string(password_hash($_POST['password'] ?? '', PASSWORD_DEFAULT));
+  $email    = $db->real_escape_string($_POST['email'] ?? '');
   $query = "INSERT INTO $table SET".
             "`username` = '".$username."', ".
             "`password` = '".$password."', ".
@@ -39,18 +39,18 @@ if (!isset($_SESSION['editor'])) {
     <script type="text/javascript" src="../utilities.js"></script>
     <link rel="alternate" type="application/rss+xml" title="xxx.org.za RSS feed" href="/feed" />
   </head>
-<? flush(); ?>
+<?php flush(); ?>
 <body>
 <div id="container">
-<? include_once("../sidebar.inc.php"); ?>
+<?php include_once("../sidebar.inc.php"); ?>
 <main id="main">
 <div id="maintext">
 
 <H1>add editor</H1>
 
-<? if ($added) { ?>
+<?php if ($added) { ?>
   <p>Added editor <?= $username ?></p>
-<? } else { ?>
+<?php } else { ?>
 
 <form action="https://xxx.org.za<?= $_SERVER['REQUEST_URI'] ?>" method="post">
   <div class="grid">
@@ -77,12 +77,12 @@ if (!isset($_SESSION['editor'])) {
 
   </div><!-- .grid -->
 </form>
-<? } ?>
+<?php } ?>
 
 </div> <!-- .maintext  -->
 </main> <!-- .main      -->
 </div> <!-- .container -->
-<? include_once("../bottombar.inc.php"); ?>
+<?php include_once("../bottombar.inc.php"); ?>
 
 </body>
 </html>