Update to libcurl v8.11.1.

Add overloaded curl_easy_setopt() for CURL_NETRC_OPTION.

New websocket demo whoing how to play server ping pong and check the result.

New HTTP authentication demo showing how to use a .netrc file to login.

Extend the FTP directory demo to show how to login using a SSH private key file.

Link against the new YuOpenSSL-3.4.