Support for Websocket compression

[bridger]

I'm curious if compression support has been considered for Websockets in NIO. I'd be interested in using it in my server-side app.

Kitura developed this package for websocket compression built on NIO's websockets. I asked about it being supported in Vapor and @tanner0101 suggested it would be very convenient to have it live directly in NIO.

How do you decide which parts of the Websocket spec are included in NIO and which are up to clients? I know Compression is an extension to Websockets, but it is pretty standard in most packages.

[Lukasa]

NIO is very reluctant to take on a dependency on zlib: in fact, we removed a previous HTTP compression library to swift-nio-extras for this very reason. I think we'd be happy to accept a patch in swift-nio-extras that implements this extension, though.