Microsoft-CISL/REEF — pull request #883 by markusweimer (2014-06-26 22:27:08+00:00)
Title: Provide ordered events to the Driver

This closes #882.

*Major changes*
* `DispatchingEStage` now has a second constructor, which creates a new one that shares the thread pool and exception handler with the given one. That constructor is used in `EvaluatorMessageDispatcher`
* Changed the order in `EvaluatorDispatcherThreads.dispatch()` to first send the event to services, then to the application
* Changed the default on `EvaluatorDispatcherThreads` to 1

*Minor code cleanups*
* `DispatchingEStage` now uses the queueLength of the underlying `ThreadPoolStage`
* Renamed `DispatchingEStage.dispatcher` to `DispatchingEStage.applicationDispatcher`