Description:
------------
DateTime:createFromFormat() and DateTime::__construct are not consistent for parsing dates.

__construct sets default time at 00:00:00
DateTime::createFromFormat() sets default time at current time

Test script:
---------------
var_export(DateTime::createFromFormat("Y-m-d","2012-05-11"));
var_export(new DateTime("2012-05-11"));


Expected result:
----------------
DateTime::__set_state(array(
   'date' => '2012-05-11 00:00:00',
   'timezone_type' => 3,
   'timezone' => 'Asia/Chongqing',
))
	DateTime::__set_state(array(
   'date' => '2012-05-11 00:00:00',
   'timezone_type' => 3,
   'timezone' => 'Asia/Chongqing',
))

Actual result:
--------------
DateTime::__set_state(array(
   'date' => '2012-05-11 18:34:45',
   'timezone_type' => 3,
   'timezone' => 'Asia/Chongqing',
))
	DateTime::__set_state(array(
   'date' => '2012-05-11 00:00:00',
   'timezone_type' => 3,
   'timezone' => 'Asia/Chongqing',
))