sorry folks, my fault
there is a wiki on how to have it done.
If you want to use jbpm.3 project and specifically jbpm4jsf used in your other project (for instance creating your own jbp-console but using existing code) you have to:
1) have jbpm.3 project compile (just follow wiki and run ant tags as described)
2) add context param to your project's web.xml file. This is necessary as jbpm4jsf uses facelets which look for xml files with tags definitions.
i don't have to add that these files can be found in jbpm.3 project :)