let config handle command line options. support long options (names are same as in config file settings) and config file creation from command line. WARNING! config layout is changed: - main options are in 'main' section (was: 'server' section); - 'log_ip' changed to 'log_hostnames' with reverse meaning to conform to '-N' command line option. - trackers are all defined in section 'trackers', with option name being tracker name (was: separate sections per tracker).