DDF-356 Added NotificationController to map userIds to CometD ServerSessions. The controller also subscribes to notifications from the OSGi eventing framework and sends them to the appropriate user via CometD.
DDF-356 Merge branch 'master' of https://github.com/codice/ddf-ui

Conflicts:
	search-ui/search-app/src/main/resources/features.xml
	search-ui/search-endpoint/pom.xml