Merge branch '2.8' into 3.4

* 2.8:
  Fix typo in the Twig article
  Removed some whitespace
  Reworded the tip contents
  Add Tip to using  MailHog during developement
  Added a small note about dynamic role hierarchies

Author: javiereguiluz

email/dev_environment.rst

@@ -246,3 +246,12 @@ you to open the report with details of the sent emails.
     by the submit URL used on the previous request (e.g. ``/contact/handle``).
     The profiler's search feature allows you to load the profiler information
     for any past requests.
+
+.. tip::
+
+    In addition to the features provided by Symfony, there are applications that
+    can help you test emails during application development, like `MailCatcher`_
+    and `MailHog`_.
+
+.. _`MailCatcher`: https://github.com/sj26/mailcatcher
+.. _`MailHog`: https://github.com/mailhog/MailHog

reference/configuration/twig.rst

@@ -128,7 +128,7 @@ format
 The format used by the ``date`` filter to display values when no specific format
 is passed as argument.
 
-internal_format
+interval_format
 ...............
 
 **type**: ``string`` **default**: ``%d days``

security.rst

@@ -1259,6 +1259,13 @@ In the above configuration, users with ``ROLE_ADMIN`` role will also have the
 ``ROLE_USER`` role. The ``ROLE_SUPER_ADMIN`` role has ``ROLE_ADMIN``, ``ROLE_ALLOWED_TO_SWITCH``
 and ``ROLE_USER`` (inherited from ``ROLE_ADMIN``).
 
+.. note::
+
+    The value of the ``role_hierarchy`` option is defined statically, so you
+    can't for example store the role hierarchy in a database. If you need that,
+    create a custom :doc:`security voter </security/voters>` that looks for the
+    user roles in the database.
+
 Final Words
 -----------