Improves compliance with RFC 7230 on the expected handling of requests
that have URI or asterisk in the request target.
This means rejecting asterisk requests that are not OPTIONS and rejecting
authority-form requests taht are not CONNECT.
This also means the server will handle the path and query on targets
with absolute URIs as request-targets.
- Replace endpoint configuration via .UseUrls() or --server.urls with Listen*
methods on KestrelSerrverOptions.
- Replace IConnectionFilter with IConnectionAdapter which no longer exposes
ServerAddress via a context.
- Simplify libuv Listener classes
- Support systemd socket activation
- Add docker-based test for systemd socket activation to be run on Travis