When requiring login signatures, order documents from oldest to newest

Summary: Depends on D18788. Ref T13024. Currently, we prompt users to sign from newest to oldest. This seems less intuitive than oldest to newest.

Test Plan: Dumped document order, saw it swap to oldest-first.

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T13024

Differential Revision: https://secure.phabricator.com/D18789

src/applications/base/controller/PhabricatorController.php

@@ -560,6 +560,7 @@ abstract class PhabricatorController extends AphrontController {
       ->setViewer($viewer)
       ->withSignatureRequired(1)
       ->needViewerSignatures(true)
+      ->setOrder('oldest')
       ->execute();
 
     $must_sign_docs = array();