4.0 Release The simplest prooph/service-bus ever

This is the fourth major release of prooph/service-bus. It was initially triggered by prooph/common v3.0 but became a complete refactoring. The entire system was reduced to the bare minimum required to do the job of dispatching messages.

We kept the event-driven approach of handling message dispatches but added some new defaults to reduce the number of required plugins (event listeners) and also the number of events being triggered during a message dispatch.
Check out the aligned documentation and the following changelog:

v4.0 was prepared in a feature branch: #55

Removed

• logger support
  • because it can simply be added with a custom plugin
• DispatchEvents: CommandDispatch, EventDispatch, QueryDispatch
  • you need to align your custom plugins, checkout the default plugins, should not be complex task
• fluent interface for $bus->utilize()->utilize() is gone!
• on/off methods of a bus, same can be achieved with $bus->getActionEventEmitter()->attachListener()
• Removed CallbackStrategy
  • a callable message handler is invoked by the message bus directly
• MessageDispatcher invoke strategies
  • with prooph/common v3.0 remote messages are gone and therefor message dispatcher and the entire message handling can be simplified

Changed

• all plugins moved to namespace Prooph\ServiceBus\Plugin
• ServiceLocatorProxy renamed to ServiceLocatorPlugin
  • works now with Interop\Container\ContainerInterface
• Removed all Message\Plugins
  • message dispatcher are now simple callables

Added

• MessageFactoryPlugin
  • can convert a message given as an array into a message object using a Prooph\Common\Messaging\MessageFactory
  • useful when a consumer of a message queue want to dispatch a message without knowing the message format