Description:
------------
PHP's IntlDateFormatter/IntlDateFormatter->format() returns zeros instead of Fractional Seconds: http://www.icu-project.org/apiref/icu4c/classSimpleDateFormat.html#details

$ aptitude search '~i icu'
i A libicu52             - International Components for Unicode

Test script:
---------------
<?php
echo "All 3 should show the fractions of second:\n";

echo var_dump((new \DateTime())->format('Y-m-d\TH:i:s.u'));

echo var_dump((new \IntlDateFormatter(
    'en-US',
    \IntlDateFormatter::FULL,
    \IntlDateFormatter::FULL,
    'UTC',
    \IntlDateFormatter::GREGORIAN,
    'yyyy-MM-dd HH:mm:ss.SSSSSS'
))->format(new \DateTime()));

echo var_dump(datefmt_create(
    'en-US',
    \IntlDateFormatter::FULL,
    \IntlDateFormatter::FULL,
    'UTC',
    \IntlDateFormatter::GREGORIAN,
    'yyyy-MM-dd HH:mm:ss.SSSSSS'
)->format(new \DateTime()));


Expected result:
----------------
Microseconds should be outputted correctly.

Actual result:
--------------
Instead you get '000000`'

See: https://3v4l.org/3pMtR