Convert PHUIObjectBoxView to AphrontTagView

Summary: Attempting to clean PHUIObjectBoxView up a little as well as finally being able to `addClass` on the sucker. I'm running into some issue with `addTabs` though, which on Files isn't firing.

Test Plan: Bounce around tons of screens.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D15291

src/applications/people/controller/PhabricatorPeopleProfileViewController.php

@@ -174,7 +174,7 @@ final class PhabricatorPeopleProfileViewController
     $box = id(new PHUIObjectBoxView())
       ->setHeader($header)
       ->appendChild($list)
-      ->setBackground(PHUIBoxView::GREY);
+      ->setBackground(PHUIObjectBoxView::GREY);
 
     return $box;
   }
@@ -218,7 +218,7 @@ final class PhabricatorPeopleProfileViewController
     $box = id(new PHUIObjectBoxView())
       ->setHeaderText(pht('Badges'))
       ->appendChild($flex)
-      ->setBackground(PHUIBoxView::GREY);
+      ->setBackground(PHUIObjectBoxView::GREY);
 
     return $box;
   }