First test to integrate device by device.

This first version tests only the velocity (SoT) -> position (HW)
scheme.
It should be able to handle acceleration (SoT) -> position/velocity (HW).
current (SoT) -> current (HW)
torque (SoT) -> torque (HW)

The following possibility is currently not handled:
current (SoT) -> position (HW)
This would requires to handle actuator model.