interface library for the Velodyne Lidar sensor.

This library can either read packets directly from the network interface
of the sensor, or read libpcap capture files containing data saved by
tcpdump. 

A test program that dumps the data in a human-readable format is included.

In this version, there is an atempt to use the algorithm provided by 
Velodyne to compute 3D points from the calibration data, but this is not
usable as is.
