previously, for some reason that i can't remember, you had to copy the jbpm libs into your ant lib directory for deployment to work properly.
i'm not completely sure that these can be removed, but i didn't get a problem yet after i had removed the jbpm libs from the ant installation.
so i deleted the ant task in jbpm to install the jbpm libs in ant and i removed that piece of the docs.
if you have worked with jbpm head after the project restructuring, check your ant-home/lib folder and delete jbpm jars from there.
clover and junit should remain there, i believe.