Updated the sonar module prototype.
The biggest change to the proposed node is a restructuring of the sonar code style. Two services (sonar_toggle and sonar_set_scan) allow another node to turn the sonar on and off. The sonar constantly scans, keeps track of its position, and publishes all its readings in the topic sonar_direction.msg....
Added the ROS stack with the libscout, motors, and sonar packages to the reposititory, and associated files. There are probably still things missing. Libscout won't run properly, but it and motors will compile. Sonar is probably broken, but nothing depends on it yet, so this shouldn't be an issue.