minor change and debug output
robot keeps driving untill obstacle is in better sight (1/2 x sensordistance)
extremes of the obstacle are published, so the algorithm can be debugged visually
minor changes to laser-data and angle limiting
minor change for memory usage.
when using the robot instead of the simulator,
don't store any obstacle data in memory,
only use on the fly data from the sensors.
publish current TF when not in simulator