Add option to operate in local mode

[kefahi]

Runtime rendering creates undesirable dependency on an external service.
Previous Plantuml dokuwiki plugins additionally offered local mode; where rendering happens at modification time.

Is it possible / easy to bring the local mode option? It would require two additional requirements: plantuml jar file and jre.

[Grief]

I doubt that jre installation could be automated. Other than that, it's possible to run self-hosted plantuml.jar and declare its url in plugin's settings.