RFR (JAXP): 8042244 : Re-examine the supportedness of non-SE org.w3c.dom.** API

[huizhe wang]

Please review the change related to the non-SE org.w3c.dom.** API: 
org.w3c.dom.css, org.w3c.dom.html, org.w3c.dom.stylesheets, 
org.w3c.dom.xpath.

They came into Java SE along with the DOM API, but were not part of the 
Java SE and JAXP specification. For css, html and stylesheets, there is 
no implementation in the Java SE,  while for xpath, an experimental one. 
These types should not be exported through the java.xml module. 
Considering that there are references to them, we're moving them into a 
JDK module called jdk.xml.dom. The experimental DOM 3 XPath thus is no 
longer available through the DOM API (DOMImplementation).

Please review:
JAXP change:
http://cr.openjdk.java.net/~joehw/jdk9/8042244/webrev/

module.xml:
http://cr.openjdk.java.net/~joehw/jdk9/8042244/jdk/webrev/

JBS: 8042244 : Re-examine the supportedness of non-SE org.w3c.dom.** API 
<https://bugs.openjdk.java.net/browse/JDK-8042244>

Thanks,
Joe