fixed NMS-6478: bad info node up/node down transaction

Created a couple of events sent by poller when an outage is created
or resolved. Those events are properly managed by rtc

Conflicts:
	features/events/api/src/main/java/org/opennms/netmgt/events/api/EventConstants.java
	opennms-services/src/main/java/org/opennms/netmgt/rtc/DataManager.java
	opennms-services/src/main/java/org/opennms/netmgt/rtc/DataUpdater.java