Eventually stop retrying port allocation if it fails repeatedly.
Properly detect socket errors caused by already-in-use addresses.
loopback() and loopbackSecure() recover gracefully if an ephemeral port is requested and the located port isn't available on both IPv4 and IPv6.HttpServer.autoCompress.Add support for HttpServer.defaultResponseHeaders.clear.
Fix HttpServer.defaultResponseHeaders.remove and .removeAll.
HttpServer.defaultResponseHeaders.