Sort Blocking Others revisions from the oldest

Test Plan: Looked at homepage and Differential homepage.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D4629

src/applications/differential/query/DifferentialRevisionQuery.php

@@ -909,7 +909,7 @@ final class DifferentialRevisionQuery {
       // it.
       if ($needs_review ^ $filter_is_author) {
         if ($needs_review) {
-          $blocking[] = $revision;
+          array_unshift($blocking, $revision);
         } else {
           $active[] = $revision;
         }