Request::get_measurements(mac) is renamed Request::get_measurement(mac).
A Request can't store more than one measurement per AP, so it was a
mistake to return a vector. The new function returns a single pointer.
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.