minor #4695 Misc changes (ifdattic)

This PR was squashed before being merged into the 2.3 branch (closes #4695).

Discussion
----------

Misc changes

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.3
| Fixed tickets |

Commits
-------

18fa2c6 Misc changes

best_practices/controllers.rst

@@ -110,8 +110,9 @@ for the homepage of our app:
          */
         public function indexAction()
         {
-            $em = $this->getDoctrine()->getManager();
-            $posts = $em->getRepository('App:Post')->findLatest();
+            $posts = $this->getDoctrine()
+                ->getRepository('AppBundle:Post')
+                ->findLatest();
 
             return $this->render('default/index.html.twig', array(
                 'posts' => $posts
@@ -136,6 +137,7 @@ For example:
 
 .. code-block:: php
 
+    use AppBundle\Entity\Post;
     use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
     
     /**
@@ -146,7 +148,7 @@ For example:
         $deleteForm = $this->createDeleteForm($post);
 
         return $this->render('admin/post/show.html.twig', array(
-            'post'      => $post,
+            'post'        => $post,
             'delete_form' => $deleteForm->createView(),
         ));
     }
@@ -188,8 +190,10 @@ flexible:
 
 .. code-block:: php
 
+    use AppBundle\Entity\Post;
     use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
     use Sensio\Bundle\FrameworkExtraBundle\Configuration\ParamConverter;
+    use Symfony\Component\HttpFoundation\Request;
 
     /**
      * @Route("/comment/{postSlug}/new", name = "comment_new")