the new 3.1.16_RELEASE_NOTES.txt file, since the merge of subtemplates was changed to allow some special conditions with {blocks} and {includes}
NOTE: Please test this Serendipity Beta with existing Blog templates and entries!
3.1.12 has minor bug fixes and improvements. Smarty also received a security fix regarding the escapement of Smarty error messages. ie. an unrealistic but testable case where you call $smarty->display($_GET['id']); and the GET value is passed directly to the error message. To resolve any probable concern, error messages are now escaped.
For details please read the Smarty 3.1.12 Change Log.