adapt to http api

http: move mux to its own file; allow to specify the mux per listen

rename client -> connection use consistently `conn' as local variable name

http: add illimitate buffering

http: add a README file

adapt to http api change

http: remove http::error, callbacks now return io::error only Having http::error being io::error plus badrequest was just a hack. There's no need to expose the private error type.

http: remove debug logging

adapt to new http:: API, try crazy stuff

http: rework req parsing; handle re-entering

http: fmt

ev: add note

ev: fmt

ev: check for fd dups

http: introduce a reswriter; change API accordingly since it uses a bufio::stream it is limited to 1024 bytes of response, an auto-resizing implementation will follow...