remove mailing list and forum references

As Stack Overflow is now the preferred web based support platform and
both the mailing list and the forum will be shut down, we should not
refer to them anymore.

Author: xabbuh

contributing/code/bugs.rst

@@ -14,8 +14,8 @@ Before submitting a bug:
 * Double-check the official :doc:`documentation </index>` to see if you're not misusing the
   framework;
 
-* Ask for assistance on the `users mailing-list`_, the `forum`_, or on the
-  #symfony `IRC channel`_ if you're not sure if your issue is really a bug.
+* Ask for assistance on `Stack Overflow`_ or on the #symfony `IRC channel`_
+  if you're not sure if your issue is really a bug.
 
 If your problem definitely looks like a bug, report it using the official bug
 `tracker`_ and follow some basic rules:
@@ -34,8 +34,7 @@ If your problem definitely looks like a bug, report it using the official bug
 
 * *(optional)* Attach a :doc:`patch <patches>`.
 
-.. _users mailing-list: http://groups.google.com/group/symfony2
-.. _forum: http://forum.symfony-project.org/
+.. _`Stack Overflow`: http://stackoverflow.com/questions/tagged/symfony2
 .. _IRC channel: irc://irc.freenode.net/symfony
 .. _tracker: https://github.com/symfony/symfony/issues
 .. _Symfony Standard Edition: https://github.com/symfony/symfony-standard/

contributing/code/security.rst

@@ -9,9 +9,9 @@ Reporting a Security Issue
 --------------------------
 
 If you think that you have found a security issue in Symfony, don't use the
-mailing-list or the bug tracker and don't publish it publicly. Instead, all
-security issues must be sent to **security [at] symfony.com**. Emails sent to
-this address are forwarded to the Symfony core-team private mailing-list.
+bug tracker and don't publish it publicly. Instead, all security issues must
+be sent to **security [at] symfony.com**. Emails sent to this address are
+forwarded to the Symfony core-team private mailing-list.
 
 Resolving Process
 -----------------