syslogd: cleanup

- simplify resolveconfig() -> now logger_lookup is also used in syslogd.c
- inline addrfds
- small cosmetical changes in parse_config_file()
syslogd: stop abusing arg_list
syslogd: cleanup

- fix bugs in previous cleanups
- remove config from struct logfile
- simplify parse_config()
syslogd: cleanup

- fix bugs introduced in the cleanups
- inline addrfds() and open_unix_socks() and simplify them
- use xpidfile()
- remove isNetwork from struct logfile
- invert the meaning of facility and level in struct logfile so
  that they are automatically correctly initialized
- fix memory leak regarding the filenames of logfiles
- TT.sd was unused