Check for pandas.core.series.Series in Mqtt actor.

Support more numpy.ndarray dtype.

Improve documentation.

- Perfomance improvement.
- Ask for MQTT username and password.

Add class diagram for AcdaqActorGui's

Acdaq baseclass are working including SerDevSim as example for a derived AcdaqDevice class.

AcdaqActor can execute quasi periodic actions in its own thread.

Basics only.