Seems like that part of integration was either dropped or moved somewhere else after 4.1 release.
If you want you give it a try with latest available version of JBoss 5 integration library:http://repository.jboss.org/maven2/org/jbpm/jbpm4/jbpm-jboss5/4.1/
Unfortunately I don't know any documentation about it. Please post back if you will try it.
HTH