Thanks Mauricio, the overall picture is challenging.
Btw, I tried to install v2 sources to have all in Eclipse.
Maven complains about 2 missing artifacts it could not download from any configured repository:
1) com.wordpress.salaboy.smarttasks:smart-tasks-api:jar:1.0-SNAPSHOT
2) com.wordpress.salaboy.smarttasks:smart-tasks-jbpm5-impl:jar:1.0-SNAPSHOT