Description:
------------
The json_encode and the json_decode functions bug with the degree character ( '?' ). 

Reproduce code:
---------------
header("content-type: text");
$test = array();
$test['data'] = "test1?test2";
echo json_encode($test) . "\r\n";
print_r(json_decode('{"data":"test1?test2"}'));

Expected result:
----------------
{"data":"test1?test2"}
stdClass Object
(
    [data] => test1?test2
)


Actual result:
--------------
{"data":"test1"}