[IO-424] Javadoc fixes, mostly to appease 1.8.0. Patch from Ville Skyttä". 3 files in the patch did not applied cleanly, so they are not in the commit.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/io/trunk@1563227 13f79535-47bb-0310-9956-ffa450edef68