Evict WorkerPool et al from core of disruptor

[grumpyjames]

These classes aren't used internally at LMAX; this makes it very difficult for us to act as maintainers of them. We're also not hugely convinced that using the disruptor in this way is a good fit for the underlying technology. I'm not going to get out the Jurassic Park scientist meme, but I feel I could.

Should we stop including those classes as part of the disruptor in 4.x? I think so...

[adol001]

In version 4.x, is there a successor to Disruptor::handleEventsWithWorkerPool? Can multiple consumers cooperate to process a batch of messages? (one message will only be processed by one consumer)

[denis-adamchuk]

FAQ still mentions WorkerPool which is confusing. Consider cleaning-it up.

[otaviocarvalho]

@grumpyjames how is that used internally at LMAX? Do you folks cover the standard way of using it somewhere (e.g. a blog post)?

[grumpyjames]

To be clear: we don't use worker pool at LMAX; that's why we feel uncomfortable supporting it.