Description:
------------
json_encode of float doesn't work when a locale is define which use comma (,) as separator (ex: fr_FR)


Test script:
---------------
$aReturn=array(
'fAmount' => 12.12
);

setlocale(LC_ALL, 'fr_FR');
print(json_encode($aReturn));

Expected result:
----------------
{"fAmount":12.12}

Actual result:
--------------
{"fAmount":12,12}