OOZIE-1473 getKey() not overridden in some commands causing duplicates in queue (virag)

git-svn-id: https://svn.apache.org/repos/asf/oozie/branches/branch-4.0@1508131 13f79535-47bb-0310-9956-ffa450edef68
OOZIE-1472 Confirm against database before generating start and duration miss events (rohini)

git-svn-id: https://svn.apache.org/repos/asf/oozie/branches/branch-4.0@1508134 13f79535-47bb-0310-9956-ffa450edef68