merged branch lukestokes/minor_session_doc_change (PR #536)

This PR was squashed before being merged into the master branch (closes #536).

Commits
-------

a9552481 Minor session documentation change.

Discussion
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Minor session documentation change.

Thanks to igorw in #silex-php, we were able to get our redis sessions
working in Silex. At his request, I'm updating the docs to indicate what
he came up with.

---------------------------------------------------------------------------

by igorw at 2012-11-08T18:26:20Z

Looks good, but please wrap the long line at 80 chars.

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by igorw at 2012-11-08T19:04:07Z

👍

doc/providers/session.rst

@@ -83,3 +83,17 @@ authenticates a user and creates a session for him::
 
         return "Welcome {$user['username']}!";
     });
+
+
+Custom Session Configurations
+-----------------------------
+
+If your system is using a custom session configuration (such as a redis handler
+from a PHP extension) then you need to disable the NativeFileSessionHandler by
+setting ``session.storage.handler`` to null. You will have to configure the
+``session.save_path`` ini setting yourself in that case.
+
+.. code-block:: php
+
+    $app['session.storage.handler'] = null;
+