If the new `publish_frame_projected_to_2d` option is set to true,
the published pose will be restricted to a pure 2D pose
(no roll, pitch, or z-offset).
This prevents potentially unwanted out-of-plane poses in 2D mode
that can occur due to the pose extrapolation step (e.g. if the pose
shall be published as a 'base-footprint'-like frame).
This adds an option to subdivide sensor_msgs/LaserScan and
sensor_msgs/MultiEchoLaserScan messages into multiple point
clouds. For slow spinning laser scanners this allows unwarping
using googlecartographer/cartographer#408.
Alexander Belyaev
Michael Grupp
Susanne Pielawa
Juraj Oršulić
Wolfgang Hess
Yutaka Takaoka