Fix Javadoc for Java 8.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/codec/trunk@1585866 13f79535-47bb-0310-9956-ffa450edef68
Add TODO.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/codec/trunk@1585867 13f79535-47bb-0310-9956-ffa450edef68