Paste - add created time to pastes in a list

Summary: Fixes T5943. We do this differently in different places; Audit / Differential do something like this while Pholio expands the "byLine" to include a timestamp. Go with the Audit / Differential approach, as presumably having the date as a top line, easily scannable metadata is the goal here.

Test Plan: viewed a list of pastes and saw a timestamp of creation at the top.

Reviewers: epriestley, chad

Reviewed By: chad

Subscribers: epriestley, Korvin

Maniphest Tasks: T5943

Differential Revision: https://secure.phabricator.com/D10338

src/applications/paste/query/PhabricatorPasteSearchEngine.php

@@ -163,6 +163,7 @@ final class PhabricatorPasteSearchEngine
         ),
         $preview);
 
+      $created = phabricator_datetime($paste->getDateCreated(), $viewer);
       $line_count = count($lines);
       $line_count = pht(
         '%s Line(s)',
@@ -176,6 +177,7 @@ final class PhabricatorPasteSearchEngine
         ->setHref('/P'.$paste->getID())
         ->setObject($paste)
         ->addByline(pht('Author: %s', $author))
+        ->addIcon('none', $created)
         ->addIcon('none', $line_count)
         ->appendChild($source_code);