Fully implement the user administration backend with drag/drop to add

users to groups.

modules/user/views/admin_users_group.html.php

@@ -1,4 +1,11 @@
 <strong><?= $group->name?></strong>
+<? if (!$group->special): ?>
+<a href="<?= url::site("users/delete_group_form/$group->id") ?>" class="gDialogLink"><?= t("delete") ?></a>
+<? else: ?>
+<span class="inactive" title="<?= t("This group cannot be deleted") ?>">
+  <?= t("delete") ?>
+</span>
+<? endif ?>
 <ul>
   <? foreach ($group->users as $i => $user): ?>
   <li class="gUser">