[MEXEC-126]
  - Make it running with Maven 2.0.11
  - Added missing extraArtifact
  - Changed maven-site-plugin from 3.1 to 2.0.1.

git-svn-id: https://svn.codehaus.org/mojo/trunk/mojo/exec-maven-plugin@19352 52ab4f32-60fc-0310-b215-8acea882cd1b