Showstopping bug: gethostname() behaving incorrectly

[John Goerzen <jgoerzen@complete.org>]

I had a problem where postfix and listar were not behaving properly.
Turns out that our gethostname() is not returning the correct value.
This can prevent everything from mail to web services from working
properly.

According to info docs and precedent, it should return a FQDN.  All
other systems, including other Linux systems, behave this way.  The
libc info docs say it should behave this way.  But it does not.

This is something that we really need fixed for potato.