Provide a mobile application menu

Summary:
Adds a right-hand-side application menu, based roughly on `frame_v3.png`.

This has the same icon as the left menu until we get real design in, but is functionally reasonable.

Test Plan: {F26170} {F26169}

Reviewers: chad

Reviewed By: chad

CC: aran

Maniphest Tasks: T1960

Differential Revision: https://secure.phabricator.com/D4061

src/applications/paste/controller/PhabricatorPasteController.php

@@ -31,4 +31,8 @@ abstract class PhabricatorPasteController extends PhabricatorController {
     return $nav;
   }
 
+  public function buildApplicationMenu() {
+    return $this->buildSideNavView(null)->getMenu();
+  }
+
 }