To generate the reference points, use only the APs at the same level as
the virtual mobile. This is very basic for now, please refer to the TODO
update for more details on what should be done.
To be consistent with the other modules, the positioning server must be
called OwlPS Positioner instead of Positioning, and the executable
owlps-positionerd (even if the daemon mode is not implemented yet).
That's a big commit for a tiny change.
Matteo Cypriani