Major cleanup from Charles Steinkuehler <charles@steinkuehler.net>:

Major cleanup from Charles Steinkuehler <charles@steinkuehler.net>:
    - Switched to getopt argument parsing
    - Added -f option to get fully qualified domain name
    - Fixed the -s (short) and -d (domain) options, which were not
      doing a gethostbyname lookup to get the FQDN before trying to
      separate the local and domain portions of the hostname.
    - Fixed probem with 'agressive setting' of the hostname...the
      previous busybox version would try to set the hostname if called
      with a non-option argument, or the -F option, even if another
      option (like -i or -s) was given.  This behavior does not match
      the net-tools hostname, which does not attempt to set anything if
      given a 'display' option, regardless of the presence/absence of
      the -F option or additional command line arguments.
    - When using a file to set the hostname, behavior now matches
      net-tools version...previous busybox version did not handle
      comments, and simply grabbed the first line from the file.