Testing Support

[JohnMurray]

Before complexity grows too much (which appears quite easy to do in an actor implementation), I need the ability to write tests both for the internal/core components and also for the user-facing bits.

I'm not sure what all of the abstractions that I'll need are, but I suspect this will emerge naturally if I am a le to test the following components:

• management thread (requires mock executors)
• executor (requires mock manager & mock/test actors)
• actors (requires mock system/executor)