Redesign the car control API to match both "physical car" and "simulatur" use-cases

[the2ndsky]

Redesign the car control API to match both "physical car" and "simulatur" use-cases.

Issues
A. There are Commands ("set speed direct") which a Simulator might (or in the case auf dash2/fork) currently doesn't support.

Alternatives:
A1. drop the "set speed direct" command
A2. build a kind of "cruise control" like system for the simulator (accelerate/brake until target speed is reached)

B. Parameter speed is handled differently

• The RC-Car uses the commands to set "speed", while Simulators (e.g. dash2 fork: https://github.com/rc-dukes/dash2/blob/master/js/remote/SimulatorVerticle.js) uses the commands to set "acceleration".

B1. modify the implemantion of the interface concerning the simulation
B2. modify the implemantion of the interface at the rc-car.