improved debug message

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1593799 13f79535-47bb-0310-9956-ffa450edef68
[MNGSITE-152]
 - Added appropriate links to download site and license location
   to fulfill the ASF requirements.


git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1593809 13f79535-47bb-0310-9956-ffa450edef68
added "Previous Vesions" section

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1593813 13f79535-47bb-0310-9956-ffa450edef68