syslogd: extended configuration options
syslogd: extended configuration options

This commit adds the option 'services.syslogd.defaultConfig', which is
the main syslog.conf file used by the daemon. Like before, That file can
be extended by means of 'services.syslogd.extraConfig'. Users who want a
completely different configuration, however, can re-define defaultConfig
to their liking.

Furthermore, the option services.syslogd.tty' is now optional: setting
its value to the empty string "" disables logging to TTY altogether.

git-svn-id: 71c8032c709790ec749031c4215f8515ac00dc5a@27769 70bd8c7a-acb8-0310-9f0d-9cc1c95dcdbb

bnordgren/nixos,bnordgren/nixos,bnordgren/nixos,bnordgren/nixos,bnordgren/nixos