Use PSR1+2 and introduce CI tests.
Add class EventDispatcherEvents, that hold all event names.
Extract complete creation and configuration into a class.

The creation and configuration will now made by the
EventDispatcherInitializer class. This also include a new feature, each
module can add a /config/event_listeners.php and
/config/event_subscribers.php which must return an array of listeners
and subscribers.
Bump branch aliases.
Update readme.