Rsyslog: New advanced Syslogger

Rsyslog: New advanced Syslogger

Sysklogd and Klogd are replaced by Rsyslogd.
Version includes libestr libfastjson and liblogging.

Rsyslog configuration:
    Two modules are used 'imuxsock' and 'imklog' which is the minimum to get the old sysklod ouput.
    Works in 'RSYSLOG_TraditionalFileFormat' which equals to the log output of the old sysklogd.
    A work directory will be included to /var/spool/rsyslog.
    Additional user configuration directory under /etc/rsyslog.d has been introduced too.
    One old sysklogd directive needed to be changed whereby ':omusrmsg:*' for emergency messages has been set (all old sysklogd configuration directives could be used in new config).
    Since Rsyslog drops his privileges (to already existing user 'syslogd'), syslogd user is now member of group tty (/etc/group), group dialout has also been tested but have had partly problems and didn´t logged persistently.
    logrotate.conf has been adapted to Rsyslog, -HUP will be send before restart so all files should be closed before rotation.

Rsyslog initscript:
    Checks if user syslogd is part of tty group otherwise a usermod includes 'syslogd' to 'tty' (needed to be done to drop the privileges).
    Bootlog lines from sysklogd has been integrated.

syslogctrl:
    Remote logging configuration is located under /etc/rsyslog.conf and works with UDP (@) and TCP (@@).
    Rsyslog restart will be executed after configuration has been saved via logs.cgi/config.dat.

Other files/changes:
    User 'klogd' has been deleted from passwd.
    rsyslogd default.conf for 'logwatch' has been activated.
    services.cgi has been adapted to rsyslog as logging and kernel logging server and a link has also been set to related logs.cgi/config.dat.
    firstsetup has been adapted to rsyslog.

Signed-off-by: Erik Kapfer <erik.kapfer@ipfire.org>