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.
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.