lazyflow: Auto-import submodules.
request_rewrite: Split threadpool and related classes into a separate module.
threadPool: Now compatible with general callables (not just requests).
- Tasks are start/resumed via the tasks __call__ method instead of via switch_to.
- Set task assigned_worker member instead of calling set_assigned_worker.
- Renamed variables to make clear that the ThreadPool can be used with any callable, not just requests.
request_rewrite: Instead of implementing set_assigned_worker() method, use a property with a custom setter.
ThreadPool: No longer a singleton, and num_workers must be specified in constructor args.
ThreadPool: Reordered class definitions in module source.
ThreadPool: queue type is configured via a constructor arg.
ThreadPool: Cleanups.
ThreadPool: Added a test for thread assignment consistency.