config/devtools: playground for developer tools

This is nothing but a prototype right now but could become pretty
useful. We want to allow our users to control most of our developer
tools without deep knowledge about Icinga Web internals.

This first prototype allows allows one to toggle the JS UI debug
window.

application/controllers/ConfigController.php

@@ -403,6 +403,14 @@ class ConfigController extends BaseConfigController
         $this->render('authentication/remove');
     }
 
+    /**
+     * Show developer tools
+     */
+    public function devtoolsAction()
+    {
+        $this->view->tabs = null;
+    }
+
     public function resourceAction($showOnly = false)
     {
         $this->view->tabs->activate('resources');

application/views/scripts/config/devtools.phtml

@@ -0,0 +1,6 @@
+<div class="controls">
+<?= $this->tabs ?>
+</div>
+<table class="avp">
+<tr><th><?= $this->translate('UI Debug') ?></th><td><a href="javascript:void(0);" onclick="icinga.ui.toggleDebug();"><?= $this->translate('toggle') ?></td></tr>
+</table>