Review request for JDK-8026021: more fix of javadoc errors and warnings reported by doclint

[christine...@oracle.com]

Hi,

Please review a fix for
https://bugs.openjdk.java.net/browse/JDK-8026021
more fix of javadoc errors and warnings reported by doclint, see the 
description

webrev: http://cr.openjdk.java.net/~cl/8026021/webrev.00/

Thanks
Christine