Merge branch '2.8' into 3.4

* 2.8:
  do not mock the session in token storage tests
  Add Occitan plural rule
  Fix security/* cross-dependencies
  Disallow illegal characters like "." in session.name
  fix rounding from string

Author: fabpot

composer.json

@@ -31,7 +31,7 @@
         "symfony/templating": "~2.8|~3.0|~4.0",
         "symfony/translation": "~2.8|~3.0|~4.0",
         "symfony/yaml": "~2.8|~3.0|~4.0",
-        "symfony/security": "~2.8|~3.0|~4.0",
+        "symfony/security": "^2.8.31|^3.3.13|~4.0",
         "symfony/security-acl": "~2.8|~3.0",
         "symfony/stopwatch": "~2.8|~3.0|~4.0",
         "symfony/console": "~3.4|~4.0",