Merge branch '5.0' into 5.1

* 5.0:
  List which values are true for %env(bool:xxx)%

Author: javiereguiluz

configuration/env_var_processors.rst

@@ -96,7 +96,8 @@ Symfony provides the following env var processors:
             ]);
 
 ``env(bool:FOO)``
-    Casts ``FOO`` to a bool:
+    Casts ``FOO`` to a bool (``true`` values are ``'true'``, ``'on'``, ``'yes'``
+    and all numbers except ``0`` and ``0.0``; everything else is ``false``):
 
     .. configuration-block::