Ported to ROS2 version of csm.

For more information about the C(anonical) Scan Matcher, see the webpage: http://purl.org/censi/2007/csm.

Note: there are two branches on the repository. The "master" branch uses GSL.

This is the csm_eigen branch, which uses the eigen library. This branch is the work of people working at U. Freiburg and Kuka, including Christoph Sprunk and Rainer Kuemmerle.