Merge pull request #577 in VECTO/vecto-sim from ~EMQUARIMA/vecto-sim:develop to develop

* commit '92f5d80c':
  adding driver action information to databus; gearbox disengages on halt action;
  Extend Driver functionality: if no operating point can be found because the vehicle already stopped and no acceleration > 0 can be achieved (e.g. because steep uphill and the gearbox is disengaged), insert a 'halt' action and drive off again