Add basic for a REST robot.
Rewrites DxlMotor so it uses descriptor

Fixes #33
Add alias in the REST Robot.
Add RemoteRobot server and client.
Add entry in the doc for remote robot
Add remote access to primitive (start/stop)
fix 9600 trick
add a square primitive
Add client/server notebook examples.
Makes flake8 happy.
Merge pull request #37 from poppy-project/remote_robot

Remote robot