Give profile menus more straightforward hide/disable/delete/default interactions

Summary:
Ref T10054.

  - Just let users delete non-builtin items.
  - Let users choose a default item explicitly.
  - Do a better job of cleaning up items which no longer exist or belong to uninstalled applications.

(NOTE) This has one user-facing change: workboards are no longer the default on projects with workboards. I think this is probably OK since we're giving users a ton of new toys at the same time, but I'll write some docs at least.

Test Plan:
  - Deleted custom items.
  - Disabled/enabled builtin items.
  - Made various things defaults.
  - Uninstalled Maniphest, saw Workboards tab disappear entirely.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10054

Differential Revision: https://secure.phabricator.com/D15089

src/applications/project/controller/PhabricatorProjectBoardViewController.php

@@ -712,16 +712,15 @@ final class PhabricatorProjectBoardViewController
         pht('Import Columns'),
         pht('Import board columns from another project.'));
 
-    $dialog = id(new AphrontDialogView())
-      ->setUser($this->getRequest()->getUser())
+
+    $cancel_uri = $this->getApplicationURI('profile/'.$project->getID().'/');
+
+    return $this->newDialog()
       ->setTitle(pht('New Workboard'))
       ->addSubmitButton('Continue')
-      ->addCancelButton($this->getApplicationURI('view/'.$project->getID().'/'))
+      ->addCancelButton($cancel_uri)
       ->appendParagraph($instructions)
       ->appendChild($new_selector);
-
-    return id(new AphrontDialogResponse())
-      ->setDialog($dialog);
   }
 
   private function noAccessDialog(PhabricatorProject $project) {