title: maven multi-module pom and jenkins jobs
body: <p>I have a hierarchy of poms, with a parent pom that all other poms inherit from (possibly transitively). How should jobs be set up in jenkins for  this ? Should there be one job pr project/pom, or just a single job pointing to the top level pom ? 
  My goal is obviously to have jenkins build only  what is required after a change. A single job pointing to the top level pom seems to rebuild everything. </p>