Merge branch '4.4' into 5.0

* 4.4:
  add ProblemNormalizer
  Update injection_types.rst
  Update associations.rst
  Update serializer.rst

Author: javiereguiluz

components/serializer.rst

@@ -678,7 +678,7 @@ There are several types of normalizers available:
     calling the constructor during the denormalization process.
 
     Objects are normalized to a map of property names and values (names are
-    generated removing the ``get``, ``set``, ``has``, ``is``, ``add`` or ``remove`` prefix from
+    generated by removing the ``get``, ``set``, ``has``, ``is``, ``add`` or ``remove`` prefix from
     the method name and transforming the first letter to lowercase; e.g.
     ``getFirstName()`` -> ``firstName``).
 
@@ -691,7 +691,7 @@ There are several types of normalizers available:
     the constructor and the "setters" (public methods starting with "set").
 
     Objects are normalized to a map of property names and values (names are
-    generated removing the ``get`` prefix from the method name and transforming
+    generated by removing the ``get`` prefix from the method name and transforming
     the first letter to lowercase; e.g. ``getFirstName()`` -> ``firstName``).
 
 :class:`Symfony\\Component\\Serializer\\Normalizer\\PropertyNormalizer`
@@ -736,6 +736,9 @@ There are several types of normalizers available:
     :class:`Symfony\\Component\\Validator\\ConstraintViolationListInterface`
     into a list of errors according to the `RFC 7807`_ standard.
 
+:class:`Symfony\\Component\\Serializer\\Normalizer\\ProblemNormalizer`
+    Normalizes errors according to the API Problem spec `RFC 7807`_.
+    
 .. _component-serializer-encoders:
 
 Encoders

doctrine/associations.rst

@@ -315,7 +315,7 @@ Saving Related Entities
 Now you can see this new code in action! Imagine you're inside a controller::
 
     // src/Controller/ProductController.php
-    namespace App/Controller;
+    namespace App\Controller;
 
     // ...
     use App\Entity\Category;

service_container/injection_types.rst

@@ -218,6 +218,9 @@ that accepts the dependency::
     {
         private $mailer;
 
+        /**
+         * @required
+         */
         public function setMailer(MailerInterface $mailer)
         {
             $this->mailer = $mailer;