* Improved DurableMailboxSpec for stand alone usage
* Changed build to publish DurableMailboxSpec in akka-mailboxes-common-test
* Changed documentation of durable mailboxes and added full example of
how to implement a durable mailbox, with test
* Changed signatures and constructor of MessageDispatcherConfigurator
* Changed Dispatchers.lookup, keep configurators instead of dispatchers
* Removed most of the Dispatchers.newX methods, newDispatcher is still there because of priority mailbox
* How should we make it easy to configure priority mailbox?
* Changed tons tests
* Documentation and ScalaDoc is not updated yet
* Some tests in ActorModelSpec are temporary ignored due to failure