[syslog-ng] throttle parser

[Fabien Wernli]

Hi,

How would you suggest to throttle matching messages in a log path?
I know there's the `throttle` option in many destinations, but I'd like to
be able to do this upstream, e.g. in patterndb or better in the path
directly.

It would be awesome to be able to do:

    log {
      source(…);
      junction {
        channel {
          filter(…);
          throttle(100);
        };
        channel {
          flags(fallback);
        };
      };
      destination(…);
    };

wouldn't it?