XNAT-4349 Cleaned up dependency issues that blocked REST implementation.

src/main/java/org/nrg/xapi/rest/event/EventHandlerApi.java

...ava/org/nrg/xapi/rest/notifications/NotificationsApi.java

src/main/java/org/nrg/xnat/configuration/WebConfig.java

src/main/java/org/nrg/xnat/services/XnatAppInfo.java

src/main/resources/org/nrg/xnat/messages/system.properties