JBPM-4106 - Process completion overrides initiator of the process
(cherry picked from commit 3de2827a43a064ce714d99dbec7c00e8f2c38431)
BZ-996586 - Insufficient error handling in email notification
(cherry picked from commit bea0e37cd9ab03cd758a78fbf1d56c4fecf063d4)
 - restoring hibernate as non-optional dependency of jbpm-test