Merge branch '2.3' into 2.7

* 2.3:
  [Finder] Partially revert #17134 to fix a regression
  [HttpKernel] Fix mem usage when stripping the prod container
  exception when registering bags for started sessions

Conflicts:
	src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php
	src/Symfony/Component/HttpKernel/Kernel.php

Author: nicolas-grekas

composer.json

@@ -22,7 +22,7 @@
     "require-dev": {
         "doctrine/common": "~2.3",
         "symfony/http-foundation": "~2.1",
-        "symfony/intl": "~2.7.4",
+        "symfony/intl": "~2.7.4|~2.8",
         "symfony/yaml": "~2.0,>=2.0.5",
         "symfony/config": "~2.2",
         "symfony/property-access": "~2.3",