* Remove DataSegmentFinder, InsertSegmentToDb, and descriptor.json file
* delete descriptor.file when killing segments
* fix test
* Add doc for ha
* improve warning
* Rename io.druid to org.apache.druid.
* Fix META-INF files and remove some benchmark results.
* MonitorsConfig update for metrics package migration.
* Reorder some dimensions in inner queries for some reason.
* Fix protobuf tests.
* Add @ExtensionPoint and @PublicApi annotations.
* Clean up wording.
* Remove unused import.
* Remove unused imports.
* Only types can be extension points.
* Adjust annotations some more.
* Remove unused import.
* Make ServletFilterHolder an extension point.
* Add a couple extension points, and update docs.
* NN optimization for hdfs data segments.
* HdfsDataSegmentKiller, HdfsDataSegment finder changes to use new storage
format.Docs update.
* Common utility function in DataSegmentPusherUtil.
* new static method `makeSegmentOutputPathUptoVersionForHdfs` in JobHelper
* reuse getHdfsStorageDirUptoVersion in
DataSegmentPusherUtil.getHdfsStorageDir()
* Addressed comments.
* Review comments.
* HdfsDataSegmentKiller requested changes.
* extra newline
* Add maprfs.