Description:
------------
When using AsXML on an element which contains children, the returned source is different from the original XML source. This prevents any direct comparison between the two.

Reproduce code:
---------------
<?php
	
	Header("Content-type: text/plain");
	
	$XML = SimpleXML_Load_String('<code>
	<a href="javascript:alert(\'1\');"><strong>Item Two</strong></a>
</code>');
	
	foreach ($XML->XPath("//*") as $Element) {
		echo Trim($Element->AsXML()), "\n--------------------\n";
	}
	
?>

Expected result:
----------------
<?xml version="1.0"?>
<code>
	<a href="javascript:alert('1');"><strong>Item Two</strong></a>
</code>
--------------------
<a href="javascript:alert('1');">
  <strong>Item Two</strong>
</a>
--------------------
<strong>Item Two</strong>
--------------------

Actual result:
--------------
<?xml version="1.0"?>
<code>
	<a href="javascript:alert('1');"><strong>Item Two</strong></a>
</code>
--------------------
<a href="javascript:alert('1');"><strong>Item Two</strong></a>
--------------------
<strong>Item Two</strong>
--------------------