* 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.
* opentsdb emitter extension
* doc for opentsdb emitter extension
* update opentsdb emitter doc
* add the ms unit to the constant name
* add a configurable event limit
* fix version to 0.13.0-SNAPSHOT
* using a thread to consume metric event
* rename method and parameter