* Clean up some of protocol abstractions
- Renamed PipeConnection to DuplexPipe
- Removed MemoryPool from ConnectionContext
- Work around value tuple issue on net471
- Most of the shared code is in the HttpProtocol class (former Frame)
- Virtual calls handle protocol-specific things
- Move the ProcessRequestsAsync loop to HttpProtocol
- Implement HTTP/1.x request processing in Http1Connection and HTTP/2
in Http2Stream, with Http1Connection<T> and Http2Stream<T> subclassing
those classes in order to handle the generic HttpContext parameter
- Split MessageBody into Http1MessageBody and Http2MessageBody,
with MessageBody containing shared member variables and methods
* Improve ConnectionLimitMiddleware and connection pipeline building
* Add IDecrementConcurrentConnectionCountFeature
* Flow connection features from connection middleware
* Added initial connection middleware pipeline
- Implemented IConnectionBuilder on ListenOptions. Kept IConnectionAdapter for now.
- Delay the configure callback for ListenOptions until the server has started.
- Added ConnectionLimitMiddleware and HttpConnectionMiddleware
- Expose ConnectionAborted and ConnectionClosed on ConnectionContext and
IConnectionTransportFeature
- Updated the tests
- Removed IConnectionApplicationFeature
- Moved Application to IConnectionTransportFeature
- Added Protocols.Abstractions
- IConnectionHandler.OnConnection takes an IFeatureCollection instead of
IConnectionInfo
- Removed IConnectionContext and IConnectionInformation replaced with
IConnectionTransportFeature
- Updated FrameConnectionContext and FrameContext to have the relevant
state instead of flowing the ConnectionInformation.
- Updated tests