Description:
------------
new DateTimeZone('PST')
and
new DateTimeZone('America/Los_Angeles')
are same.

please, modify getTimezone()->getName() output.
thank you.

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

$datetime = new DateTime('Dec-01-08 08:17:40 PST');
echo "new PST\n";
echo $datetime->getTimezone()->getName();
echo "\n";
echo $datetime->format('Y-m-d H:i:s');
echo "\n";
$pst = new DateTimeZone('PST');
$datetime->setTimezone($pst);
echo "DateTimeZone PST\n";
echo $datetime->getTimezone()->getName();
echo "\n";
echo $datetime->format('Y-m-d H:i:s');
echo "\n";
$kst = new DateTimeZone('KST');
$datetime->setTimezone($kst);
echo "DateTimeZone KST\n";
echo $datetime->getTimezone()->getName();
echo "\n";
echo $datetime->format('Y-m-d H:i:s');
echo "\n";

?>


Expected result:
----------------
new PST
PST
2008-12-01 08:17:40
DateTimeZone PST
America/Los_Angeles
2008-12-01 08:17:40
DateTimeZone KST
Asia/Seoul
2008-12-02 01:17:40


Actual result:
--------------
new PST
America/Los_Angeles
2008-12-01 08:17:40
DateTimeZone PST
America/Los_Angeles
2008-12-01 08:17:40
DateTimeZone KST
Asia/Seoul
2008-12-02 01:17:40