minor #3937 properly escape backslashes in class and method directives (xabbuh)

This PR was merged into the 2.5 branch.

Discussion
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properly escape backslashes in class and method directives

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.5+
| Fixed tickets |

Commits
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6c4421b properly escape backslashes in class and method directives

Author: weaverryan

book/security.rst

@@ -1105,7 +1105,7 @@ authorization from inside a controller::
     The ``createAccessDeniedException`` method was introduced in Symfony 2.5.
 
 The :method:`Symfony\\Bundle\\FrameworkBundle\\Controller\\Controller::createAccessDeniedException`
-method creates a special :class:`Symfony\\Component\\Security\\Core\Exception\\AccessDeniedException`
+method creates a special :class:`Symfony\\Component\\Security\\Core\\Exception\\AccessDeniedException`
 object, which ultimately triggers a 403 HTTP response inside Symfony.
 
 Thanks to the SensioFrameworkExtraBundle, you can also secure your controller using annotations::

components/class_loader/psr4_class_loader.rst

@@ -59,7 +59,7 @@ first need to configure the ``Psr4ClassLoader``:
 
 First of all, the class loader is loaded manually using a ``require``
 statement, since there is no autoload mechanism yet. With the
-:method:`Symfony\Component\ClassLoader\Psr4ClassLoader::addPrefix` call, you
+:method:`Symfony\\Component\\ClassLoader\\Psr4ClassLoader::addPrefix` call, you
 tell the class loader where to look for classes with the
 ``Symfony\Component\Yaml\`` namespace prefix. After registering the autoloader,
 the Yaml component is ready to be used.