Description:
------------
xsltProcessor->setParameter() ignores its first parameter "namespace URI" and set NULL to namespace.

Reproduce code:
---------------
$xmlStr = '<?xml version="1.0" encoding="UTF-8"?><root/>';
$xmlDom = new DomDocument();
$xmlDom->loadXML($xmlStr);

$xslDom = new DomDocument();
$xslDom->load("./testcase.xsl");

$proc = new xsltProcessor();
$proc->importStyleSheet($xslDom);

/* set a parameter WITH namespace */
$proc->setParameter("http://www.php.net/test", "foo", "SET");

print $proc->transformToXML($xmlDom);

---- testcase.xsl
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                              xmlns:test="http://www.php.net/test">
    <xsl:param name="foo" select="'EMPTY'"/>
    <xsl:param name="test:foo" select="'EMPTY'"/>

    <xsl:template match="/root">
        <xsl:text>Namespace "NULL": </xsl:text>
        <xsl:value-of select="$foo"/>
        <xsl:text>, Namespace "http://www.php.net/test": </xsl:text>
        <xsl:value-of select="$test:foo"/>
    </xsl:template>
</xsl:stylesheet>

Expected result:
----------------
Namespace "NULL": EMPTY, Namespace "http://www.php.net/test": SET

Actual result:
--------------
Namespace "NULL": SET, Namespace "http://www.php.net/test": EMPTY