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).

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.

err/warn is not available on some systems (unfortunately!) and in any case don't play well with our daemon mode (that closes std{in,out,err}). Use our fatal that is daemon-aware.

we don't fork anymore in that process, so the flag is extra.

cgi.c wasn't really needed; it better to group all the server related functions together, cgi or not. Now gmid.c contains only startup and utility code.