Hydro/catkin support

During our migration to hydro, I converted the SnapMap package to catkin and made it compatible with pcl 1.7.
This is the result, it is not pretty and the package name does not conform with catkin naming conventions, but it works with groovy and hydro in a catkin workspace.
In groovy, you need to rosdep install SnapMapICP first to get the pcl 1.7 library.