Refactor setting socket options

[falbrechtskirchinger]

Add detail::set_socket_opt() and detail::set_socket_opt_time() to avoid repetition of platform-specific code.

[falbrechtskirchinger]

@yhirose MaxTimeoutTest still times out on MacOS occasionally. Why not call SSL_set_shutdown() with SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN and close the socket, when the timeout has been exceeded, instead of properly shutting down via SSL_shutdown()?

[yhirose]

@yhirose MaxTimeoutTest still times out on MacOS occasionally. Why not call SSL_set_shutdown() with SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN and close the socket, when the timeout has been exceeded, instead of properly shutting down via SSL_shutdown()?

Could you please send another pull request for this?

[yhirose]

@falbrechtskirchinger thanks for the excellent improvement!

[falbrechtskirchinger]

@yhirose MaxTimeoutTest still times out on MacOS occasionally. Why not call SSL_set_shutdown() with SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN and close the socket, when the timeout has been exceeded, instead of properly shutting down via SSL_shutdown()?

Could you please send another pull request for this?

After studying the man pages of the relevant calls, I rewrote ssl_delete, but it's still struggling on MacOS. I may try again tomorrow; I have another idea similar to what's being done in ssl_connect_or_accept_nonblocking().