RFR 9: (doclint) 8181156 html5 doclint issues in java.base javadoc

[Roger Riggs]

Please review javadoc markup change to update to html5 acceptable to 
doclint.
The table formatting is updated to html5 markup.

The Docs build is updated to require doclint html5.
Webrev:
  jdk: http://cr.openjdk.java.net/~rriggs/webrev-base-html5-8181156/
  build: http://cr.openjdk.java.net/~rriggs/webrev-top-html5-8181156/

Issue:
https://bugs.openjdk.java.net/browse/JDK-8181156 html5 doclint issues in 
java.base javadoc

Thanks, Roger