xwiki-platform-tool-packager-plugin considers ${project.version} to be the version to use for xwiki artifacts it depends on

In various places, the PackageMojo, to resolve xwiki artifacts, considers their version to be this.getProject().getVersion(), equivalent to "${project.version}".
Obviously, if using the packager plugin from an independant contribution/project (with versions not synchronized with XE), it does not work, and fails to retrieve the needed artifacts from Nexus.