LASzip: 2.0.2 - lossless LiDAR compression

Add a formula for LASzip, a tool for losslessly compressing las files
(http://asprs.org/Committee-General/LASer-LAS-File-Format-Exchange-Activities.html).
LASzip is used in several other libraries, including liblas
(http://www.liblas.org/) and PDAL (http://www.pointcloud.org/).

This forumla includes a url for a HEAD install.