Swap "Create Task" button over to EditEngine

Summary: Ref T9132. I can't actually get rid of the EditController yet since a few weird things still use it, but I think I can swap this button out without breaking anything. This will let us do "New Feature Request" / "New Bug" / "Advanced Task Creation" on secure and start playing with this stuff sooner.

Test Plan: Clicked "Create Task", got sent to new form.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T9132

Differential Revision: https://secure.phabricator.com/D14673

src/applications/maniphest/controller/ManiphestController.php

@@ -30,11 +30,9 @@ abstract class ManiphestController extends PhabricatorController {
   protected function buildApplicationCrumbs() {
     $crumbs = parent::buildApplicationCrumbs();
 
-    $crumbs->addAction(
-      id(new PHUIListItemView())
-        ->setName(pht('Create Task'))
-        ->setHref($this->getApplicationURI('task/create/'))
-        ->setIcon('fa-plus-square'));
+    id(new ManiphestEditEngine())
+      ->setViewer($this->getViewer())
+      ->addActionToCrumbs($crumbs);
 
     return $crumbs;
   }