[rules-dev] Recursion bug in JBoss TMS

I've encountered a NPE in TruthMaintananceSystem:304 on retractions of tracked facts (because getLogicalDependencies() returns null). I hunted it down to DefaultKnowledgeHelper::setActivation() method. A comment there says that this was added to resolve the JBRULES-2558 bug. My attempt to fix it is attached - instead of removing the list of logical dependencies, I instead track re-additions and then remove everything else.