Test cleanup
General cleanup
Escalation improvements

- escalations are referenced by their "escalationCode" attr values
- exceptions thrown when syntax is incorrect (no escalationRef in escalation end event)
JBPM-3785 JBPM-4052: Compensation execution
JBPM-3785 JBPM-4052: Compensation parsing
JBPM-3785 JBPM-4052: Compensation tests
Seperating intermediate escalation, compensation and error tests into their own class