Retired (deleted) unused packages.
Moved their msg/srv definitions to the messages/ package instead, and revised the libscout and scoutsim files that depended on those namespaces.
Removed bom.cpp, bom.h, get_bom_reading.srv, and query_sonar.srv
Removed them for real this time; not pretend
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.