[various] Rename group to circle

- Drop support for group_text
- Add support for circle_text

diaspora/diaspora.php

@@ -205,7 +205,7 @@ function diaspora_send(array &$b)
 	$b['body'] = Post\Media::addAttachmentsToBody($b['uri-id'], DI::contentItem()->addSharedPost($b));
 
 	// Dont't post if the post doesn't belong to us.
-	// This is a check for forum postings
+	// This is a check for group postings
 	$self = DBA::selectFirst('contact', ['id'], ['uid' => $b['uid'], 'self' => true]);
 
 	if ($b['contact-id'] != $self['id']) {