this also gives a chance for users to use the default host even if SNI is missing.

the new logging code was crashing if the client didn't support SNI or if required an unknown vhost: this because we short-circuit in handle_handshake to an error, so c->iri isn't populated yet (we don't even read the request). fixes #1

now we log the full IRI requested (before was only the path) and the response line (even for CGI).

alpine on amd64 (under OpenBSD vmd) tries to do a clock_gettime. I don't know why, but it doesn't seem a problem to allow it.

allow only the F_GETFL and F_SETFL commands

was probably added to distinguish between AF_INET and AF_INET6, to use different functions for logging. But it wasn't really used, and now we use getnameinfo anyway.