Costbalancer Multithread
Extracted common methods
Test udpate
fixes to comments
configurable thread count
Dynamic Config
Removed CostBalancerStrategy, made default = 1 thread
millis converted.
minor changes from review
One CostBalancerStrategy
revert
comments
commonalize event receiver firehose
add bindings for chat handler provider
Add chatHandlerResource
moved file
fix casing issue when parsing event
support for null values in DimExtractionFn
support for null values in group-by
requires druid-api update