Remove all code referencing old tab navigation

Summary:
  - Add getHelpURI() to PhabricatorApplication for application user guides.
  - Add a new "help" icon menu item and skeletal Diviner application.
  - Move help tabs to Applications where they exist, document the other ones that don't exist yet.
  - Grep for all tab-related stuff and delete it.

Test Plan: Clicked "help" for some apps. Clicked around randomly in a bunch of other apps.

Reviewers: btrahan, vrana

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D3267

src/applications/phame/controller/PhameController.php

@@ -39,14 +39,6 @@ abstract class PhameController extends PhabricatorController {
     $page->setTitle(idx($data, 'title'));
     $page->setGlyph("\xe2\x9c\xa9");
 
-    $tabs = array(
-      'help' => array(
-        'name' => 'Help',
-        'href' =>
-          PhabricatorEnv::getDoclink('article/Phame_User_Guide.html'),
-      ),
-    );
-    $page->setTabs($tabs, idx($data, 'tab'));
     if ($this->showSideNav()) {
       $nav = $this->renderSideNavFilterView($this->getSideNavFilter());
       $nav->appendChild($view);