Simple Executor class gives a pass-through submit method
Include futures as requirement
If constructed, executor auto-wraps function calls on the thing it wraps with a call to submit
Four use cases now supported
Dropped prints
Using a thread provider to when doing submit
ParallelExecutor *is* an Executor
Extracted managed thread functions out of ServiceContainer
Use threads in parallel executor
Some class documentation
Wrap submit call results in a sort-of Future class
Use real Futures with the Executor
Provider can inform about running threads at teardown
Improve test coverage
Test exception raised if leaving running threads
Merge branch 'evolutionary' into parallel-execution-provider-1938b

Conflicts:
	nameko/service.py
Improve coverage, check exception forwarded to Future
Pre code review
Test that stopping the container escapes you from long running threads
Better documented the ManagedThreadContainer class vs ServiceContainer