SwiftNIO 2.1.0

Semver Minor

• Added an API to construct a ByteBuffer from a ByteBufferView. (#958)
• Added an API to limit the maximum buffer size of a ByteToMessageDecoder. (#957, #998)
• Extended NonBlockingFileIO to allow opening a file for writing. (#975, #990)
• Added NIOCloseOnErrorHandler. (#967)
• Conformed HTTPMethod to RawRepresentable with a raw type of String. (#976)
• Added an API to get a ChannelHandler from the pipeline. (#974)
• Made ChannelOptions.Storage initializer public. (#988)
• Renamed WebSocketUpgrader to NIOWebSocketServerUpgrader and deprecated the old name. (#983)

Semver Patch

• Improved performance by rewriting internal Heap implementation. (#960)
• Fixed example HTTP server to avoid crashing when serving an empty file. (#962)
• Removed invalid assert in CircularBuffer that caused crashes on 32 bit architectures. (#978)
• Fixed a bug where HTTPDecoder would incorrectly retain too many bytes, and replay them on handler removal in some cases. (#984)
• Made MarkedCircularBuffer implementation @inlineable. (#993)
• Improved the performance of constructing HTTPHeaders from an array of tuples. (#994)
• Fixed an issue where HTTPDecoder would crash if it received a response without headers. (#997)
• Added a link to GitHub implementation in documentation. (#977)
• Started testing on Swift 5.1. (#991, #995)
• Various documentation cleanups. (#979, #989)
• Removed some warnings in the tests. (#982)
• Started using new allocation test framework. (#996)