RFR: 8037948: Improve documentation for org.w3c.dom package

[huizhe wang]

Hi,

This is a quick fix for a broken link in org.w3c.dom package. Also 
included is removal of unnecessary (and bad) link to jaxp api in a 
catalog class. Please review.

http://cr.openjdk.java.net/~joehw/jdk9/8037948/webrev/

Thanks,
Joe