Review and fix all the tests so that 100% of the tests pass.
There are still many compilation warning and many tests fail, but at least everything builds.
This fixes an old, forgotten, vocabulary mistake.
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.