Carve out a separate "Modules/Extensions" section of Config

Summary:
Ref T13362. Config is currently doing a ton of stuff and fairly overwhelming. Separate out "Modules/Extensions" so it can live in its own section.

(This stuff is mostly useful for development and normal users rarely need to end up here.)

Test Plan: Visited seciton, clicked around. This is just a visual change.

Maniphest Tasks: T13362

Differential Revision: https://secure.phabricator.com/D20930

src/applications/config/application/PhabricatorConfigApplication.php

@@ -63,7 +63,7 @@ final class PhabricatorConfigApplication extends PhabricatorApplication {
           'purge/' => 'PhabricatorConfigPurgeCacheController',
         ),
         'module/' => array(
-          '(?P<module>[^/]+)/' => 'PhabricatorConfigModuleController',
+          '(?:(?P<module>[^/]+)/)?' => 'PhabricatorConfigModuleController',
         ),
         'cluster/' => array(
           'databases/' => 'PhabricatorConfigClusterDatabasesController',

src/applications/config/controller/PhabricatorConfigController.php

@@ -42,13 +42,6 @@ abstract class PhabricatorConfigController extends PhabricatorController {
       pht('Repository Servers'), null, 'fa-code');
     $nav->addFilter('cluster/search/',
       pht('Search Servers'), null, 'fa-search');
-    $nav->addLabel(pht('Modules'));
-
-    $modules = PhabricatorConfigModule::getAllModules();
-    foreach ($modules as $key => $module) {
-      $nav->addFilter('module/'.$key.'/',
-        $module->getModuleName(), null, 'fa-puzzle-piece');
-    }
 
     return $nav;
   }

src/applications/config/controller/PhabricatorConfigModuleController.php

@@ -8,6 +8,11 @@ final class PhabricatorConfigModuleController
     $key = $request->getURIData('module');
 
     $all_modules = PhabricatorConfigModule::getAllModules();
+
+    if (!strlen($key)) {
+      $key = head_key($all_modules);
+    }
+
     if (empty($all_modules[$key])) {
       return new Aphront404Response();
     }
@@ -16,13 +21,27 @@ final class PhabricatorConfigModuleController
     $content = $module->renderModuleStatus($request);
     $title = $module->getModuleName();
 
-    $nav = $this->buildSideNavView();
-    $nav->selectFilter('module/'.$key.'/');
+    $nav = new AphrontSideNavFilterView();
+    $nav->setBaseURI(new PhutilURI($this->getApplicationURI()));
+
+    $modules_uri = $this->getApplicationURI('module/');
+
+    $modules = PhabricatorConfigModule::getAllModules();
+
+    foreach ($modules as $module_key => $module) {
+      $nav->newLink($module_key)
+        ->setName($module->getModuleName())
+        ->setHref(urisprintf('%s%s/', $modules_uri, $module_key))
+        ->setIcon('fa-puzzle-piece');
+    }
+
+    $nav->selectFilter($key);
     $header = $this->buildHeaderView($title);
 
     $view = $this->buildConfigBoxView($title, $content);
 
     $crumbs = $this->buildApplicationCrumbs()
+      ->addTextCrumb(pht('Extensions/Modules'), $modules_uri)
       ->addTextCrumb($title)
       ->setBorder(true);