* Tackling some low hanging performance fruit
- Use native Memory/Span APIs on Stream and WebSocket in .NET Core 2.1
- Remove double copying in formatters
- Implemented custom HttpContent over ReadOnlyBuffer<byte>
* Remove the Channel<HubMessage> from the HubConnectionContext
- Replace the channel with a single lock around the pipewriter. Since writes are always synchronous, the lock is held for a very short time.
- We were only using them in this scenario for handling multiple producers (the hub output, the keep alive ping and the broadcast).
- Handle the scenario where there's back pressure (when we use pipes that are bounded) and give callers a single task representing when back pressure is released.
- Handle synchronous exceptions in RedisHubLifetimeManager
- Fixed benchmarks