scheme (like im* and om*)

- added -M rsyslogd option (allows to specify module directory location)
- converted net.c into a loadable library plugin

    made this mode the default; this was needed, as some programs (e.g.
    sshd) log with inconsistent timezone information, what messes up the
    local logs (which by default don't even contain time zone information).
    This seems to be consistent with what sysklogd did for the past four
    years. Alternate behaviour may be desirable if gateway-like processes
    send messages via the local log slot - in this case, it can be enabled
    via the $InputUnixListenSocketIgnoreMsgTimestamp and
    $SystemLogSocketIgnoreMsgTimestamp config directives

    own class and converted to new object calling conventions
    (interface-based)
- converted gss-misc into a loadable library module

- moved module loader from conf.c to module.c, where it belongs
- made the necessary plumbing to auto-load library modules
- upgraded debug system to include iRet in function exit message
- changed module interface so that instances need only to be supported by
    output plugins (if we actually need them for input plugins, we can
    always add it again...)
- milestone: first implementation of library modules (but do not get
    unloaded on exit/hup so far)

- changed module interface version, as the interface change is quite large

    - http://bugzilla.adiscon.com/show_bug.cgi?id=6