Do not save session on builder complete

[marcinus]

In Cognifide, we usually have our groovy scripts controlled by DRY_RUN flag. When set to true, changes are not persisted by calling session.refresh(false), otherwise session.save() is called.

However, nodeCompleted function explicitely saves the session (see in code):

@Override
void nodeCompleted(parent, node) {
    session.save()

    currentNode = currentNode.parent
}

It would be great if this behaviour could be controlled (saving prevented), either by some global flag, or in builder's constructor.