str_map::key_cmp -> str_map::key_xfrm

It seemed to be almost too easy to be true, and it actually was.

Now it should work.
Only print the first OpenSSL error

Otherwise TLS autodetection and TLS communication itself seem to work, yay!
Revise usage of print_{error,fatal}()

Let's limit print_fatal() to unexpected conditions.

Also added exit_fatal() to save a few lines of code.
Implement daemonization

Now we're a real daemon, yay.