Replace graceful/hard shutdown combo with simple exit
Remove unused class
Add RealtimeMetricsMonitor to RealtimeIndexTask
More controllable realtime shutdown

- Realtime plumber will start persisting segments shortly after finishJob is called, regardless
  of rejection policy

- Add "none" rejection policy
RealtimeIndexTask: Allow configurable rejection policies
IndexerCoordinatorResource: Log when remote task action fails
Fix busted condition
RemoteTaskActionClient: Fix http path
ForkingTaskRunner: Use guava Closer to closer stuff
RealtimePlumberSchool: Persist and merge immediately upon finishJob
RemoteTaskActionClient: Log service uri when submitting action
[maven-release-plugin] prepare release druid-0.5.20
[maven-release-plugin] prepare for next development iteration
added close methods on inputSupplier tests
[maven-release-plugin] prepare release druid-0.5.21
[maven-release-plugin] prepare for next development iteration
Merge pull request #199 from metamx/indexing-service-mods

Improve robustness and usability of RealtimeIndexTask and some code cleanup in the Indexing Service
[maven-release-plugin] prepare release druid-0.5.22
[maven-release-plugin] prepare for next development iteration
Merge branch 'master' into worker-resource