Adds toString() to simplify debugging process

git-svn-id: https://svn.apache.org/repos/asf/struts/struts2/trunk@1487417 13f79535-47bb-0310-9956-ffa450edef68
Uses proper logging structure

git-svn-id: https://svn.apache.org/repos/asf/struts/struts2/trunk@1487418 13f79535-47bb-0310-9956-ffa450edef68