v2.5.0.M1

Announce post : https://spring.io/blog/2016/02/16/reactor-2-5-a-second-generation-reactive-foundation-for-the-jvm

First 2.5.x re-organized Reactor Core iteration

• Flux, Mono rx lite API for at most N or at most 1 sequences
• Environment/Dispatcher -> SchedulerGroup
• RingBufferProcessor -> TopicProcessor
• RingBufferWorkProcessor -> WorkQueueProcessor
• PublisherFactory -> Flux
• Subscribers and Subscriptions utils for custom operator
• Flow and State representation for graph introspection
• TestSubscriber
• full javadoc