Prepare for 0.4.0.M1

Docs tweaking and package info renaming in README.md
@benjchristensen maybe I misunderstood something about the `Processor` interface, but a processor being both a subscriber and a publisher makes it inherently hot. So how come it can have only 1 subscriber?

Also, why should the processor cancel its subscription after all subscribers have canceled? Maybe one wants to keep the connection active. Again I may be thinking of the wrong analogy from Rx - but it makes sense in many instances to keep alive a connectable observable, even if at some point it has no subscribers - because you may want to cache it (BehaviorSubject, ReplaySubject, etc...) and because reconnecting later may be expensive, so I see no problem with a hot publisher or a processor choosing to keep a connection active for the entire lifetime of the application, should it choose to do so.

In my opinion, what happens to that connection after subscribers have canceled their subscription should be left to the implementation of the publisher. Why should the contract specify what happens to that connection?