Integrate slope lidar

[m3d]

The slope lidar is used on robot Eduro to scan traversibility of the surface in front of the robot. Current mounting corresponds to 60 cm height and 145cm readings -> 25deg

>>> math.degrees(math.asin(60/145))
24.443335427697384

Note, that the slope lidar is relatively sparse and has to be integrated into some local map otherwise obstacles like wooden barrier would be overlooked (it is visible at some distance but if you move closer it "disappears").