My last improvements before 1.7.0RC1.

Can include Cc & Bcc on mail.
Send mail to all administrators on new comment or new users.
Add validate link on new comment mail.
Try to detect if the NBM complementary content is HTML or plain text. With plain text, this content is convert to readable HTML.

git-svn-id: http://piwigo.org/svn/trunk@1818 68402e56-0260-453c-a942-63ccdbb3a9ee

register.php

@@ -70,11 +70,14 @@ if (isset($_POST['submit']))
         .'Browser: '.$_SERVER['HTTP_USER_AGENT']."\n\n"
         .l10n('admin').': '.$admin_url;
 
-      pwg_mail(get_webmaster_mail_address(),
+      pwg_mail
+      (
+        format_email('administrators', get_webmaster_mail_address()),
         array
         (
           'subject' => 'PWG '.l10n('register_title').' '.$username,
-          'content' => $content
+          'content' => $content,
+          'Bcc' => get_administrators_email()
         )
       );
     }