[ticket/11749] PHP and Template Events for Topic Preview Extension

http://tracker.phpbb.com/browse/PHPBB3-11749

[PHP] core.search_modify_tpl_ary  http://area51.phpbb.com/phpBB/viewtopic.php?f=111&t=43763
[PHP] core.search_get_topic_data  http://area51.phpbb.com/phpBB/viewtopic.php?f=111&t=43765
[PHP] core.viewforum_get_shadowtopic_data  http://area51.phpbb.com/phpBB/viewtopic.php?f=111&t=44057
[PHP] core.viewforum_get_topic_data  http://area51.phpbb.com/phpBB/viewtopic.php?f=111&t=43761
[Template] topiclist_row_append / prepend  http://area51.phpbb.com/phpBB/viewtopic.php?f=111&t=44409