Fixed maven build when druid is integrated as a submodule
fix segment metadataquery
Merge pull request #584 from metamx/fix-segment-metadata-query

fix segment metadataquery
prepare for next release
[maven-release-plugin] prepare release druid-0.6.121
[maven-release-plugin] prepare for next development iteration
reduce memory usage for end points

do not copy entire segments when not needed,
reduces memory pressure on the coordinator when no. of segments is
large enough.
remove duplicate code
improve mem usage for getLoadStatus
Merge pull request #585 from metamx/coordinator-mem-usage

reduce coordinator mem usage
modify whirr documentation
revert changes to wikipedia_realtime_task.json, CliBroker.java, CliHistorical.java
revert changes to wikipedia_realtime_task.json, CliBroker.java, CliHistorical.java
add dependencies for validator error
Merge pull request #586 from metamx/jisoo

modify whirr documentation
address code review
update dep version
fix index task new schema defaults
add default tuning config for index task
hdfs data segment killer

implement hdfs data segment killer