Integrate uuid generation into the core of the model system so items are uniquely identified and can be directly accessed using their uuids.

For example:
// set recurring pipe item to 1001
$model->setNodeByReference('pipes.pipe.86f19d48-bc91-4c70-a81c-e05cdd3a4372.queue', "1001");

// echo the contents back
echo $model->getNodeByReference('pipes.pipe.86f19d48-bc91-4c70-a81c-e05cdd3a4372.queue');

(proxy) check for existing log file in diag_logs_proxy.php (https://github.com/opnsense/core/issues/186 )

Hopefully approved by: ad@
Inspired by: service(8)

- remove unused L2 ipfw support
- redirect after login was duplicate, remove one
- reload ipfw rules on zone save

Submitted by: @reetp