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
druid header
small perf test
limit on balancer compute threads

max being no. of processors - 1
Merge pull request #399 from metamx/multithread-costbalancer

Multithread costbalancer