FALCON-710 start/end is optional for lifecycle operations. Contributed by Balu Vellanki
FALCON-828 Add hadoop version info as part of falcon admin version API. Contributed by Venkatesh Seetharam
FALCON-831 Operation on non existing entity throws internal server error. Contributed by Venkatesh Seetharam
FALCON-834 Propagate request id in the response to help trace and debug failures in merlin. Contributed by Venkatesh Seetharam