* Deduplicate DataSegments contents (loadSpec's keys, dimensions and metrics lists as a whole) more aggressively; use ArrayMap instead of default LinkedHashMap for DataSegment.loadSpec, because they have only 3 entries on average; prune DataSegment.loadSpec on brokers
* Fix DataSegmentTest
* Refinements
* Try to fix
* Fix the second DataSegmentTest
* Nullability
* Fix tests
* Fix tests, unify to use TestHelper.getJsonMapper()
* Revert TestUtil as ServerTestHelper, fix tests
* Add newline
* Fix indexing tests
* Fix s3 tests
* Try to fix tests, remove lazy caching of ObjectMapper in TestHelper, rename TestHelper.getJsonMapper() to makeJsonMapper()
* Fix HDFS tests
* Fix HdfsDataSegmentPusherTest
* Capitalize constant names
* add jq expression in the flattenSpec
* more tests
* add benchmark
* fix style
* use JsonNode for both JSONPath and JQ
* clean up
* more clean up
* add documentation
* fix style
* move jackson-jq version to dependencyManagement section. remove commented code
* oops. revert wrong fix
* throw IllegalArgumentException for JQ syntax error
* remove e.printStackTrace() that is forbidden
* touch
* Exclude the transitive dependency LGPL jar since it is not needed
* add reason why exclude
* exclude from the root dependency
* add banning tool to enforce exclusions
* Fix parsing fail of segment id with underscored datasource (Fix for #2786)
* addressed comment
* renamed and moved code into api. added log4 dependency for tests
* addressed comments
* fixed test fails