Changes

Mark class Bus as deprecated. Need use EventBus class;
Mark interface BusInterface as deprecated. Need use EventBusInterface interface;
Added support for deferred publication of events by QueueEventBus;
Implementations of simple queues are added:
- MemoryEventQueue - storage of events in memory, in the current PHP process;
- MemoryUniqueEventQueue - storage of unique events in memory, in the current process;
- PredisEventQueue - storage of events in Redis using predis/predis;
- PredisUniqueEventQueue - storage of unique events in Redis using predis/predis.

Provide feedback