Description:
------------
Even when setting the locale to one that uses commas for the decimal point separator in a floating point number, the FILTER_VALIDATE_FLOAT and FILTER_SANITIZE_NUMBER_FLOAT constants do not recognize the comma as a proper separator. For internationalization, these filters should allow the comma (or take the locale into account and allow the comma).

Reproduce code:
---------------
<?php

setlocale(LC_ALL, 'de_DE');

$float1 = '42.3';
$float2 = '42,3';

var_dump(filter_var($float1, FILTER_VALIDATE_FLOAT));
var_dump(filter_var($float2, FILTER_VALIDATE_FLOAT));

var_dump(filter_var($float1, FILTER_SANITIZE_NUMBER_FLOAT, array('flags' => FILTER_FLAG_ALLOW_FRACTION)));
var_dump(filter_var($float2, FILTER_SANITIZE_NUMBER_FLOAT, array('flags' => FILTER_FLAG_ALLOW_FRACTION)));

?>

Expected result:
----------------
float(42.3)
float(42.3)
string(4) "42.3"
string(4) "42.3"

Actual result:
--------------
float(42.3)
bool(false)
string(4) "42.3"
string(3) "423"