Adding back in JMS Bundles

Added the JMS bundles that were removed in Symfony 2.3.
NOTE: these bundles were removed for GNU license complience. Adding
them back in makes this repo no longer compatible with GPLv2 licensed
projects
Fixed accidentally removed status code in app/check.php
merged branch maxromanovsky/app-config-status-code-fix (PR #553)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #553).

Discussion
----------

Fixed accidentally removed status code in app/check.php

Commits
-------

bbf5680 Fixed accidentally removed status code in app/check.php
updated VENDORS for 2.3.0
Merge tag 'v2.3.0' of github.com:symfony/symfony-standard into 2.3

created tag 2.3.0