Refactoring/rewrite of modal boxes handling

app/Template/group_modification/show.php

@@ -1,7 +1,7 @@
 <div class="page-header">
     <h2><?= t('Edit group') ?></h2>
 </div>
-<form class="popover-form" method="post" action="<?= $this->url->href('GroupModificationController', 'save') ?>" autocomplete="off">
+<form method="post" action="<?= $this->url->href('GroupModificationController', 'save') ?>" autocomplete="off">
     <?= $this->form->csrf() ?>
 
     <?= $this->form->hidden('id', $values) ?>
@@ -10,9 +10,5 @@
     <?= $this->form->label(t('Name'), 'name') ?>
     <?= $this->form->text('name', $values, $errors, array('autofocus', 'required', 'maxlength="100"')) ?>
 
-    <div class="form-actions">
-        <button type="submit" class="btn btn-blue"><?= t('Save') ?></button>
-        <?= t('or') ?>
-        <?= $this->url->link(t('cancel'), 'GroupListController', 'index', array(), false, 'close-popover') ?>
-    </div>
+    <?= $this->modal->submitButtons() ?>
 </form>