Create MeasurementGrid from LiDAR point cloud

[TheCodez]

TODO:

• Use PCL
• Cleanup code
• Improve API
• Python KITTI data preparation

Example on KITTI LiDAR:

Currently on:
https://github.com/TheCodez/dynamic-occupancy-grid-map/tree/lidar_meas_grid

[TheCodez]

Mostly blocked by #70 because of the PCL dependency.