LaserScannerLocalization: incomplete scan

If only a single object is in the scene, the laser scanner simulation might not detect the object.

Reason:

• Initially an occupancy grid is created which is approx. the size of the bounding box of all objects.
• The robot is not added to the occupancy grid, therefore the robot might be outside of the occupancy grid.
• If so, no objects will be detected

@paus.fabian FYI