Add perf classpath to IDEA module configuration.
Make it possible to include custom event processors in a chain of dependencies via an EventProcessorFactory rather than having to break the chain and use asSequenceBarrier. This approach also enables custom event processors to use pollers instead of barriers.
Make EventHandler contravariant in EventHandlerGroup and make WorkHandler contravariant.
Pass the ringBuffer to EventProcessorFactory.createEventProcessor instead of making each instance fetch it from the disruptor.