[MNGSITE-152] added license and download links

git-svn-id: https://svn.apache.org/repos/asf/maven/enforcer/trunk@1605193 13f79535-47bb-0310-9956-ffa450edef68
[MNGSITE-152] moved license and download links to release root

git-svn-id: https://svn.apache.org/repos/asf/maven/enforcer/trunk@1605465 13f79535-47bb-0310-9956-ffa450edef68