Created a simple locomotor model to control Roomba in a more easy and
generic way
Simple test to verify the roomba locomotor model
computes the derived velocity/radius when the last command was a direct drive (rigth+left wheel speeds)
moved the socket thread safety in the client itself (it was before on the user side)
few more tests
adapted to use the unified driveVelocity and simplified using the Roomba locomotor model