Merge branch '2.6' into 2.7

* 2.6:
  [FrameworkBundle] fix browserkit requirement
  [FrameworkBundle] fix expression-language requirement
  [TwigBridge] fix form requirement
  [Filesystem] restore ability to create broken symlinks
  [FrameworkBundle] fix http-foundation requirement
  [CssSelector] added the license of the Python library we ported to PHP
  [SecurityBundle] avoid unneeded work

Author: nicolas-grekas

composer.json

@@ -17,7 +17,7 @@
     ],
     "require": {
         "php": ">=5.3.3",
-        "symfony/event-dispatcher": "2.5.*,>2.5.8|~2.6,>2.6.1",
+        "symfony/event-dispatcher": "~2.5.9|~2.6,>=2.6.2",
         "symfony/http-foundation": "~2.5,>=2.5.4",
         "symfony/debug": "~2.6",
         "psr/log": "~1.0"