Merge branch '2.7' into 2.8

* 2.7:
  Remove symfony/polyfill-ctype where not needed
  Use symfony/polyfill-ctype
  [Form] fixes instance variable phpdoc in FormRegistry class

Author: nicolas-grekas

composer.json

@@ -16,7 +16,8 @@
         }
     ],
     "require": {
-        "php": ">=5.3.9"
+        "php": ">=5.3.9",
+        "symfony/polyfill-ctype": "~1.8"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\Filesystem\\": "" },