Operation system worker thread names

[IrlJidel]

Currently all filter/output worker threads appear with name [#{pipeline_id}]-pipeline-manager.

(This is longer than the 15chars normally visible in OS.)

This behaviour contradicts the documentation
and pipeline workers show up as [base]>workerN, where N is an integer.

I believe the fix is simple and you just need to use Util.set_thread_name in start_workers in java_pipeline.rb and pipeline.rb