Added event for removed comments with some refactoring

app/Template/notification/comment_remove.php

@@ -0,0 +1,7 @@
+<h2><?= $this->text->e($task['title']) ?> (#<?= $task['id'] ?>)</h2>
+
+<h3><?= t('Comment removed') ?></h3>
+
+<?= $this->text->markdown($comment['comment']) ?>
+
+<?= $this->render('notification/footer', array('task' => $task, 'application_url' => $application_url)) ?>