Change double quotes to single quotes.

Summary: Ran `arc lint --apply-patches --everything` over rP, mainly to change double quotes to single quotes where appropriate. These changes also validate that the `ArcanistXHPASTLinter::LINT_DOUBLE_QUOTE` rule is working as expected.

Test Plan: Eyeballed it.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin, hach-que

Differential Revision: https://secure.phabricator.com/D9431

src/applications/phriction/controller/PhrictionDiffController.php

@@ -114,7 +114,7 @@ final class PhrictionDiffController
       pht('History'),
       PhrictionDocument::getSlugURI($slug, 'history'));
 
-    $title = pht("Version %s vs %s", $l, $r);
+    $title = pht('Version %s vs %s', $l, $r);
 
     $header = id(new PHUIHeaderView())
       ->setHeader($title);