OOZIE-1507 Command queue filling up with duplicate commands from RecoveryService (rohini)

git-svn-id: https://svn.apache.org/repos/asf/oozie/trunk@1516892 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk
Merge remote branch 'origin/trunk' into trunk-gd