Back up to maven-checkstyle-plugin 2.9.1 from 2.10. 2.10 seems to scan the 'target' dir and wants license headers in .properties to be the header for Java files. Drawback: there are two reports now.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/codec/trunk@1465317 13f79535-47bb-0310-9956-ffa450edef68