api: allow sorting headlines by title

classes/api.php

@@ -202,6 +202,9 @@ class API extends Handler {
 
 			$override_order = false;
 			switch ($_REQUEST["order_by"]) {
+				case "title":
+					$override_order = "ttrss_entries.title";
+					break;
 				case "date_reverse":
 					$override_order = "score DESC, date_entered, updated";
 					break;