Merge branch '2.8' into 3.0

* 2.8:
  [HttpKernel] Add listener that checks when request has both Forwarded and X-Forwarded-For
  [HttpKernel] Move conflicting origin IPs handling to catch block
  [travis] Fix deps=low/high patching

Author: fabpot

Resources/config/web.xml

@@ -38,5 +38,9 @@
             <argument type="service" id="request_stack" />
             <tag name="kernel.event_subscriber" />
         </service>
+
+        <service id="validate_request_listener" class="Symfony\Component\HttpKernel\EventListener\ValidateRequestListener">
+            <tag name="kernel.event_subscriber" />
+        </service>
     </services>
 </container>

composer.json

@@ -23,7 +23,7 @@
         "symfony/config": "~2.8|~3.0",
         "symfony/event-dispatcher": "~2.8|~3.0",
         "symfony/http-foundation": "~2.8|~3.0",
-        "symfony/http-kernel": "~2.8|~3.0",
+        "symfony/http-kernel": "~2.8.8|~3.0.8|~3.1.2|~3.2",
         "symfony/polyfill-mbstring": "~1.0",
         "symfony/filesystem": "~2.8|~3.0",
         "symfony/finder": "~2.8|~3.0",