Change simple template dashboard to "Open Tasks" instead of "All Tasks"

Summary: "All Tasks" is bad in the long run and not clearly better for new installs.

Test Plan: Created a new smiple template, saw open tasks only.

Reviewers: chad

Reviewed By: chad

Differential Revision: https://secure.phabricator.com/D16093

src/applications/dashboard/controller/PhabricatorDashboardEditController.php

@@ -268,10 +268,10 @@ final class PhabricatorDashboardEditController
           $request,
           $viewer,
           'query',
-          pht('Recent Tasks'),
+          pht('Open Tasks'),
           array(
             'class' => 'ManiphestTaskSearchEngine',
-            'key' => 'all',
+            'key' => 'open',
           ));
         $panel_phids[] = $task_panel->getPHID();