git-svn-id: https://svn.apache.org/repos/asf/maven/maven-1/plugins/trunk@292325 13f79535-47bb-0310-9956-ffa450edef68
We must edit maven-xdoc.dtd in the src/dtd directory but never maven-xdoc-${currentRelease}.dtd in ${plugin.resources}/dtd.
We store maven-xdoc-${currentRelease}.dtd in the SCM to be able to re-publish them if necessary.