Register official JodaModule to nflow-ObjectMapper in engine
Clone nflow-ObjectMapper into nflow-rest-ObjectMapper and actually use it in nflow-jetty
Return executionStartTime and -EndTime to ISO-8601 format instead of milliseconds
Added integration test for workflow action history
Actually removed custom JacksonJodaModule and used JodaModule in nflow-tests
Make sure WorkflowDispatchers wakes up often enough to keep the database keepalive stamp moving even if workflows are progressing slowly