Description:
------------
json_encode is using the decimal separator of the current locale instead of using "."
(similar to http://bugs.php.net/bug.php?id=40235)

Reproduce code:
---------------
<?php
var_dump(json_encode(1.2));
setlocale(LC_NUMERIC, 'hu_HU');
var_dump(json_encode(1.2));
?>

Expected result:
----------------
string(3) "1.2"
string(3) "1.2"

Actual result:
--------------
string(3) "1.2"
string(3) "1,2"