Update maven-changes-plugin to 2.11.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/beanutils/trunk@1628486 13f79535-47bb-0310-9956-ffa450edef68
Use ${commons.changes.version}.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/beanutils/trunk@1628487 13f79535-47bb-0310-9956-ffa450edef68