vdemo

Previous approach didn't allow for truly parallel starting of components.
Also, the level order was not considered when manually starting several groups in parallel.
The new fully event-based scheme, should resolve those issues. Please report any open issues.

Attention: The remark from previous change still holds true:
Before, components were started in given order, -w option specifying to wait for a component before proceeding to the next.
Now, all components on the same level are started in parallel. -w option simply states the timeout period, before we give up to wait for this component to be ready.