added @author tag to java files missing it; updated checkstyle dep

Added @author tag to main Java files that were missing it per https://www.pivotaltracker.com/story/show/69655652

Also was able to update to the latest version of maven-checkstyle-plugin, 2.12.1

This removes the need for us to continue maintaining https://github.com/futures/maven-checkstyle-plugin. The bug that necessitated that fork has been fixed: http://jira.codehaus.org/browse/MCHECKSTYLE-169.