[MPMD-167] CPD performance issues
Submitted by Andreas Dangel

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1478323 13f79535-47bb-0310-9956-ffa450edef68
[MPMD-169] Support multi-threaded mode of PMD 5
Submitted by Andreas Dangel

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1478324 13f79535-47bb-0310-9956-ffa450edef68