Suppress timestamp comment in generated Javadoc. Such as
<!-- Generated by javadoc (version 1.7.0_65) on Wed Oct 22 09:10:36 EST 2014 -->

Those comments result in one changed line per each HTML file,
which makes the diff between different versions of documentation unnecessary huge.

Documentation:
http://docs.oracle.com/javase/7/docs/technotes/tools/solaris/javadoc.html#standard

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1633500 13f79535-47bb-0310-9956-ffa450edef68